A student volunteer at a weather station collected the average temperature for each month in the city of Lakeview, a northern U.S. city near a large lake. Each value is the average of the daily temperatures recorded during that month, combined over many years so that one unusually warm or cold year does not distort the results. She wants to share the data on a science fair poster so that visitors can quickly see how temperature changes through the seasons.
Month
Average temperature (°F)
January
24
February
28
March
38
April
49
May
60
June
70
July
75
August
73
September
66
October
53
November
40
December
29
The student wants a display that shows clearly how Lakeview's average temperature changes over the year. Which display is best?
Hint
Which kind of graph is designed to show change over time? Also think about which variable goes on which axis.
Step-by-step solution
Where the answer comes from: the table lists one average temperature for each of the 12 months, in order from January to December. The goal is to show change over time.
Step by step:
Data that change over time are best shown with a line graph: the line makes rises and falls easy to see.
Time (here, month) is the independent variable. By convention it goes on the horizontal (x) axis, and the measured value (temperature) goes on the vertical (y) axis.
Choice B swaps the axes, which makes the trend hard to read and breaks the convention.
Choice C, a circle graph, shows parts of a whole. Monthly temperatures are not parts of a total, so slices would mean nothing.
Choice D puts the months in alphabetical order (April, August, December…), which destroys the time order you need to see the pattern.
Correct answer: A.
Tip: Match the display to the job: line graph = change over time; bar graph = compare separate categories; circle graph = parts of a whole; scatter plot = relationship between two measured variables.
Question 2 of 36
A Year of Temperatures
A student volunteer at a weather station collected the average temperature for each month in the city of Lakeview, a northern U.S. city near a large lake. Each value is the average of the daily temperatures recorded during that month, combined over many years so that one unusually warm or cold year does not distort the results. She wants to share the data on a science fair poster so that visitors can quickly see how temperature changes through the seasons.
Month
Average temperature (°F)
January
24
February
28
March
38
April
49
May
60
June
70
July
75
August
73
September
66
October
53
November
40
December
29
Which sentence best describes the data in words?
Hint
Find the lowest and highest values and the months they occur. Then check whether the change is steady.
Step-by-step solution
Where the answer comes from: the table's lowest value is January (24 °F) and its highest is July (75 °F). After July the values fall: August 73, September 66, October 53, November 40, December 29 °F.
Step by step:
From January to July, temperatures rise every month (24 → 28 → 38 → 49 → 60 → 70 → 75).
From July to December, they fall every month (75 → 73 → 66 → 53 → 40 → 29).
A complete description gives the overall pattern and the key numbers: low in January, peak in July, falling after.
A is wrong: temperatures do not rise all year. C is wrong: August (73 °F) is lower than July (75 °F). D is wrong: monthly changes vary (for example, +4 from January to February but +11 from March to April).
Correct answer: B.
Tip: A good data description names the trend (rises, falls, peaks, levels off), gives the key values with units, and makes no claim the numbers do not show.
Question 3 of 36
A Year of Temperatures
A student volunteer at a weather station collected the average temperature for each month in the city of Lakeview, a northern U.S. city near a large lake. Each value is the average of the daily temperatures recorded during that month, combined over many years so that one unusually warm or cold year does not distort the results. She wants to share the data on a science fair poster so that visitors can quickly see how temperature changes through the seasons.
Month
Average temperature (°F)
January
24
February
28
March
38
April
49
May
60
June
70
July
75
August
73
September
66
October
53
November
40
December
29
The student will graph the data for her poster. Which title is most appropriate for the graph?
Hint
A good title says exactly what was measured, where, and in what units — and nothing more.
Step-by-step solution
Where the answer comes from: the passage says the data are "the average temperature for each month in the city of Lakeview," and the table's units are °F.
Step by step:
A scientific graph title should name the variable measured, the subject or place, and ideally the units or time span.
Choice A does all three: average monthly temperature, Lakeview, °F.
Choice B makes a cause-and-effect claim (temperature causes seasons) that the data do not show — and that is not scientifically accurate (Earth's tilt causes the seasons).
Choice C names the wrong variable: the data are temperatures, not rainfall.
Choice D describes only one month, but the graph shows all twelve.
Correct answer: A.
Tip: Titles, axis labels and units are part of expressing scientific information. On the GED, the best title is accurate and complete without adding claims.
Question 4 of 36
Ramp Height and a Rolling Toy Car
A student tested how the height of a ramp affects how far a toy car rolls across the floor after leaving the ramp. She used the same car, the same ramp board and the same smooth tile floor for every trial. For each height, she released the car from the top of the ramp three times and averaged the distances.
Ramp height (cm)
Average distance rolled (cm)
10
55
20
110
30
160
40
215
The student will make a final graph with ramp height on the horizontal axis. Which pair of axis labels is best?
Hint
A good axis label names the exact variable and gives its unit. Check that the units match the table.
Step-by-step solution
Where the answer comes from: the table header "| Ramp height (cm) | Average distance rolled (cm) |" names both variables and their units.
Step by step:
The question says ramp height goes on the horizontal axis, so distance goes on the vertical axis.
Each label should name the variable clearly and give its unit in parentheses: centimeters for both.
"Height" and "Distance" with no units leave a reader guessing whether the numbers are inches, centimeters or meters.
Swapping the labels contradicts the plan, and "seconds" is not a unit of distance.
Correct answer: C.
Check: read the label back with a value: "Ramp height: 30 cm; Average distance rolled: 160 cm." It makes sense, so the labels work.
Tip: On the GED, the best axis label is specific (what was measured) and includes units. Missing or wrong units are the most common trap.
Question 5 of 36
Ramp Height and a Rolling Toy Car
A student tested how the height of a ramp affects how far a toy car rolls across the floor after leaving the ramp. She used the same car, the same ramp board and the same smooth tile floor for every trial. For each height, she released the car from the top of the ramp three times and averaged the distances.
Ramp height (cm)
Average distance rolled (cm)
10
55
20
110
30
160
40
215
How should the ramp height and the distance rolled be classified in this experiment?
Hint
The independent variable is what the scientist changes on purpose. The dependent variable is what she measures.
Step-by-step solution
Where the answer comes from: the student changed the ramp height on purpose and measured how far the car rolled. The passage also says "She used the same car, the same ramp board and the same smooth tile floor for every trial."
Step by step:
Independent variable: the factor the scientist changes on purpose = ramp height.
Dependent variable: the factor that is measured and may change in response = distance rolled.
Controlled variables: factors kept the same = the car, the ramp board and the floor.
So the car is a controlled variable, not the dependent variable, and ramp height is not controlled, because it was changed.
Correct answer: B.
Check: fill in the sentence "The distance rolled depends on the ramp height." The variable after "depends on" is the independent one.
Tip: Use the "depends on" test to keep independent and dependent variables straight.
Question 6 of 36
How Often Earthquakes Happen
Seismologists sort earthquakes by magnitude, a number that describes how much energy an earthquake releases. The table shows the average number of earthquakes recorded worldwide each year in four magnitude ranges, based on many years of records.
Magnitude range
Average number per year
5.0–5.9
1,300
6.0–6.9
130
7.0–7.9
15
8.0 and higher
1
Each step up of 1.0 in magnitude means an earthquake releases about 32 times as much energy.
A student wants to display the table to compare the number of earthquakes in the four magnitude ranges. Which display is most appropriate?
Hint
Ask what kind of data the table holds: separate categories, change over time, parts of a whole, or pairs of measurements?
Step-by-step solution
Where the answer comes from: the table lists one number for each of four magnitude ranges, from "| 5.0–5.9 | 1,300 |" to "| 8.0 and higher | 1 |".
Step by step:
The data are counts for separate categories (magnitude ranges). Comparing categories is the job of a bar graph.
A line graph shows change over time, but the table has no years.
A scatter plot needs two measured values for each item; the table does not list energy values.
A map needs locations, which the table does not include.
Correct answer: D.
Check: a bar graph lets the reader see at a glance that the 5.0–5.9 bar is far taller than the others.
Tip: Match the display to the data's job: categories → bar graph; change over time → line graph; parts of a whole → circle graph; two measured variables → scatter plot.
Question 7 of 36
Hot spotAn Energy Pyramid for a Grassland
An energy pyramid is a model that shows how energy moves through the feeding levels of an ecosystem. Each level is drawn on top of the level it eats. The pyramid shows a grassland food chain, with the energy available at each level in kilocalories (kcal) per square meter per year.
The same food chain can be written with arrows:
grass → grasshoppers → frogs → snakes → hawks
Scientists name the levels this way:
Producers make their own food from sunlight.
Primary consumers eat producers.
Secondary consumers eat primary consumers.
Tertiary consumers eat secondary consumers, and so on up the chain.
At each level, most of the energy is used for living (moving, growing, staying warm) or is lost as heat. Only about 10% is passed to the next level up.
Click the level of the pyramid that shows the secondary consumers.
Click on the figure to mark your answer (or focus it and use the arrow keys).
Hint
Start at the bottom with the producers. Secondary consumers eat the level that eats the producers.
Step-by-step solution
Where the answer comes from: the passage defines "Producers make their own food from sunlight.", "Primary consumers eat producers." and "Secondary consumers eat primary consumers." The chain is "grass → grasshoppers → frogs → snakes → hawks".
Step by step:
Grass makes its own food from sunlight, so grass is the producer (bottom level).
Grasshoppers eat grass, so they are primary consumers (second level).
Frogs eat grasshoppers, so frogs are secondary consumers (third level, 200 kcal).
Snakes are tertiary consumers, and hawks are the next level above them.
Correct answer: the frogs level (200 kcal).
Check: count up from the bottom: producer (1st), primary (2nd), secondary (3rd). The third level from the bottom is frogs.
Tip: On model questions, match each scientific term to its definition in the passage, then find that piece in the diagram. Do not guess from the size of the level.
Question 8 of 36
An Energy Pyramid for a Grassland
An energy pyramid is a model that shows how energy moves through the feeding levels of an ecosystem. Each level is drawn on top of the level it eats. The pyramid shows a grassland food chain, with the energy available at each level in kilocalories (kcal) per square meter per year.
The same food chain can be written with arrows:
grass → grasshoppers → frogs → snakes → hawks
Scientists name the levels this way:
Producers make their own food from sunlight.
Primary consumers eat producers.
Secondary consumers eat primary consumers.
Tertiary consumers eat secondary consumers, and so on up the chain.
At each level, most of the energy is used for living (moving, growing, staying warm) or is lost as heat. Only about 10% is passed to the next level up.
In the food chain written with arrows, what does the arrow in grasshoppers → frogs represent?
Hint
Look at how energy moves up the pyramid. Which way does energy go when one animal eats another?
Step-by-step solution
Where the answer comes from: the chain is written "grass → grasshoppers → frogs → snakes → hawks", and the passage says "Each level is drawn on top of the level it eats." In the pyramid, frogs sit above grasshoppers.
Step by step:
Frogs are above grasshoppers in the pyramid, so frogs eat grasshoppers.
In a food chain, the arrow points from the food to the eater. It shows the direction energy flows.
So grasshoppers → frogs means energy moves from grasshoppers to frogs when frogs eat grasshoppers.
Correct answer: C.
Check: follow the chain from grass upward. The arrow "grass → grasshoppers" must mean grasshoppers eat grass, because grass cannot eat anything.
Tip: In food chains and food webs, read the arrow as "is eaten by" or "gives energy to." Reversing the arrow is the most common mistake.
Question 9 of 36
Four Data Sets, Four Displays
A science teacher gives her class four data sets and asks the students to pick the best way to display each one.
Data set 1 — Gases in dry air: nitrogen 78%, oxygen 21%, argon 0.93%, all other gases 0.07%. Together these make up 100% of dry air.
Data set 2 — Carbon dioxide (CO₂) in the air at a mountain observatory, yearly average: 2015: 400 ppm; 2016: 404; 2017: 406; 2018: 408; 2019: 411; 2020: 414; 2021: 416; 2022: 418; 2023: 421 ppm. (ppm = parts per million.)
Data set 3 — Vertebrate species recorded in a state park: fish 42, amphibians 11, reptiles 18, birds 160, mammals 37.
Data set 4 — Height and arm span of 30 adult volunteers: each person's height (cm) and arm span (cm) were measured, giving 30 pairs of numbers, to see whether taller people tend to have longer arm spans.
Which sentence most accurately describes Data set 2 in words?
Hint
Check the direction of every year-to-year change, then find the average change per year.
Step-by-step solution
Where the answer comes from: Data set 2 lists CO₂ values of 400 ppm (2015), 404, 406, 408, 411, 414, 416, 418 and 421 ppm (2023).
Step by step:
Direction: every value is higher than the one before, so CO₂ rose every year.
Total change: 421 - 400 = 21 ppm.
Number of yearly steps: 2015 to 2023 is 2023 - 2015 = 8 years.
Average rate: \dfrac{21\text{ ppm}}{8\text{ years}} \approx 2.6 ppm per year. The individual steps were 2 to 4 ppm.
A is wrong: 421 is only about 5% more than 400. C is wrong because no year went down. D uses 21 ppm per year, which is the total change, not the yearly rate.
Correct answer: B.
Tip: When you describe a trend, say the direction and the size. Rate of change = change in value ÷ change in time. Count the intervals (8), not the data points (9).
Question 10 of 36
Drag and dropFour Data Sets, Four Displays
A science teacher gives her class four data sets and asks the students to pick the best way to display each one.
Data set 1 — Gases in dry air: nitrogen 78%, oxygen 21%, argon 0.93%, all other gases 0.07%. Together these make up 100% of dry air.
Data set 2 — Carbon dioxide (CO₂) in the air at a mountain observatory, yearly average: 2015: 400 ppm; 2016: 404; 2017: 406; 2018: 408; 2019: 411; 2020: 414; 2021: 416; 2022: 418; 2023: 421 ppm. (ppm = parts per million.)
Data set 3 — Vertebrate species recorded in a state park: fish 42, amphibians 11, reptiles 18, birds 160, mammals 37.
Data set 4 — Height and arm span of 30 adult volunteers: each person's height (cm) and arm span (cm) were measured, giving 30 pairs of numbers, to see whether taller people tend to have longer arm spans.
Drag the best type of display to each data set. One display will not be used.
Data set 1: Gases in dry air
Data set 2: CO₂ by year
Data set 3: Species by group
Data set 4: Height and arm span
Tap a tile, then tap a box to place it.
Hint
Ask of each data set: parts of a whole? change over time? separate categories? two measurements for each individual?
Step-by-step solution
Where the answer comes from: the passage describes each data set.
Step by step:
Data set 1 gives percentages that "together … make up 100% of dry air." Parts of a whole → circle graph.
Data set 2 gives one value per year from 2015 to 2023. Change over time → line graph.
Data set 3 compares five separate groups (fish, amphibians, reptiles, birds, mammals). Categories have no order or in-between values → bar graph.
Data set 4 has "30 pairs of numbers" (height, arm span) and asks whether one tends to increase with the other. Relationship between two measured variables → scatter plot.
A Punnett square predicts offspring from a genetic cross. It does not display any of these data sets, so it is the unused tile.
Correct answers: Data set 1 → circle graph; Data set 2 → line graph; Data set 3 → bar graph; Data set 4 → scatter plot.
Tip: Memorize the four "jobs": parts of a whole, change over time, compare categories, relationship between two variables. Then match each data set to its job.
Question 11 of 36
Bird Species in Four Habitats
Volunteers in a citizen-science project surveyed birds in four habitats near the same town: a forest, a wetland, a grassland and an urban park. During one spring, the volunteers spent the same number of hours watching birds in each habitat, at the same times of day. They recorded the number of different bird species (kinds of birds) seen in each habitat, not the total number of individual birds. A species seen many times was still counted only once per habitat. The results are shown in the bar graph.
Which statement correctly describes the data in the graph?
Hint
Read the exact height of each bar before you compare.
Step-by-step solution
Where the answer comes from: the bar graph shows forest 34, wetland 41, grassland 18 and urban park 12 species.
Step by step:
Most species: wetland (41). Fewest: urban park (12). So statement C is true.
A says "half as many as the wetland." Half of 41 is about 20.5, but the urban park had 12 — much less than half.
B lists the habitats as if they decrease in the order forest → wetland → grassland → urban park, but the wetland (41) had more than the forest (34).
D says habitats with more trees "always" have more species. The wetland, not the forest, had the most species, and the graph does not measure trees at all.
Correct answer: C.
Tip: In words, the safest accurate descriptions name the highest and lowest values correctly. Be suspicious of ratios ("half," "twice") — check them with the numbers.
Question 12 of 36
Drop-downBird Species in Four Habitats
Volunteers in a citizen-science project surveyed birds in four habitats near the same town: a forest, a wetland, a grassland and an urban park. During one spring, the volunteers spent the same number of hours watching birds in each habitat, at the same times of day. They recorded the number of different bird species (kinds of birds) seen in each habitat, not the total number of individual birds. A species seen many times was still counted only once per habitat. The results are shown in the bar graph.
Complete the summary of the bird survey.
The wetland had as many bird species as the urban park. The difference between the habitat with the most species and the habitat with the fewest species was species.
Choose an answer from each menu.
Hint
For "as many as," divide. For "difference," subtract.
Step-by-step solution
Where the answer comes from: the graph shows wetland 41 species (the most) and urban park 12 species (the fewest).
Step by step:
Ratio: 41 \div 12 \approx 3.4. The wetland had more than three times as many species as the urban park.
Difference between most and fewest: 41 - 12 = 29 species.
Check the traps: 23 is 41 - 18 (the grassland, not the fewest); 22 is 34 - 12 (the forest, not the most); 53 is 41 + 12 (added instead of subtracting).
Correct answers: b1 = more than three times; b2 = 29.
Tip: Words like "times as many" call for division; "difference," "how many more" and "how many fewer" call for subtraction. Make sure you pick the correct two bars before you calculate.
Question 13 of 36
A Model of the Water Cycle
Energy from the sun drives the water cycle, which moves water between Earth's surface and the atmosphere. Scientists use these terms to describe its main processes:
Evaporation — liquid water at the surface of an ocean, lake or river turns into water vapor (a gas).
Transpiration — plants release water vapor into the air through tiny openings in their leaves.
Condensation — water vapor cools and changes into tiny liquid droplets, forming clouds.
Precipitation — water falls from clouds to the surface as rain, snow, sleet or hail.
Runoff — water flows over the land surface into streams, rivers and the ocean.
The diagram is a model of the water cycle. Each numbered arrow shows one process.
Which term names the process shown by arrow 2 in the model?
Hint
At arrow 2, water vapor is entering the cloud. What happens to vapor when it forms a cloud?
Step-by-step solution
Where the answer comes from: in the diagram, arrow 2 points from rising water vapor into the cloud. The passage defines condensation as "water vapor cools and changes into tiny liquid droplets, forming clouds."
Step by step:
Follow arrow 2: it starts in the air (water vapor that rose from the ocean) and ends in the cloud.
Clouds are made of tiny liquid droplets, so at this step a gas is changing into a liquid.
Gas → liquid with cooling = condensation.
Evaporation (A) is liquid → gas at the surface; that is arrow 1. Precipitation (C) is water falling from the cloud; that is arrow 3. Transpiration (D) is vapor released by plants; that is arrow 5.
Correct answer: B.
Tip: Scientific vocabulary questions often hinge on a direction: evaporation goes up from the surface as gas; condensation forms droplets in the air; precipitation comes down.
Question 14 of 36
Hot spotA Model of the Water Cycle
Energy from the sun drives the water cycle, which moves water between Earth's surface and the atmosphere. Scientists use these terms to describe its main processes:
Evaporation — liquid water at the surface of an ocean, lake or river turns into water vapor (a gas).
Transpiration — plants release water vapor into the air through tiny openings in their leaves.
Condensation — water vapor cools and changes into tiny liquid droplets, forming clouds.
Precipitation — water falls from clouds to the surface as rain, snow, sleet or hail.
Runoff — water flows over the land surface into streams, rivers and the ocean.
The diagram is a model of the water cycle. Each numbered arrow shows one process.
Click the arrow in the model that represents precipitation.
Click on the figure to mark your answer (or focus it and use the arrow keys).
Hint
Precipitation moves water in one direction: from a cloud to the ground.
Step-by-step solution
Where the answer comes from: the passage defines precipitation as "water falls from clouds to the surface as rain, snow, sleet or hail." In the diagram, only arrow 3 starts at the cloud and points down to the land.
Step by step:
Arrow 1 rises from the ocean — evaporation.
Arrow 2 enters the cloud — condensation.
Arrow 3 falls from the cloud to the land — precipitation. ✓
Arrow 4 flows along the ground into the ocean — runoff.
Arrow 5 rises from the tree's leaves — transpiration.
Correct answer: arrow 3.
Tip: In a model or diagram, read each arrow as "from → to." The starting point and the ending point tell you which process it shows.
Question 15 of 36
Voltage and Current in a Simple Circuit
A student built a simple circuit with a battery pack, a 10-ohm (Ω) resistor and an ammeter, a meter that measures electric current in amperes (A). She changed the voltage of the battery pack and recorded the current each time. The resistor stayed the same.
Voltage (V)
Current (A)
1.5
0.15
3.0
0.30
4.5
0.45
6.0
0.60
Her teacher explained a rule called Ohm's law: the current through a resistor equals the voltage across it divided by the resistance. So with a larger resistance, the same voltage pushes less current through the circuit.
For the science fair, the student needs a title for her graph of current and voltage. Which title would communicate her results most clearly?
Hint
A good graph title names the variables that were changed and measured, and the conditions, without giving an opinion.
Step-by-step solution
Where the answer comes from: the circuit used "a 10-ohm (Ω) resistor", and "She changed the voltage of the battery pack and recorded the current each time."
Step by step:
The variables graphed are voltage (changed) and current (measured).
The resistor was the same throughout, so naming it (10 Ω) tells readers the conditions.
"Current Through a 10-Ω Resistor at Different Voltages" includes all of this.
"My Circuit Experiment" is too vague. "Ohm's Law Is Always True" is a claim, not a description of the data. Time was not measured, so "Over Time" is wrong.
Correct answer: B.
Check: a reader should be able to guess the axes from the title alone: voltage on one axis, current on the other.
Tip: Strong graph titles follow the pattern "[Measured variable] at Different [Changed variable]" plus key conditions.
Question 16 of 36
Squeezing Air in a Syringe
A student sealed the tip of a plastic syringe so that no air could get in or out. She pushed on the plunger with different forces and read the volume of trapped air from the scale on the syringe. A pressure gauge attached to the syringe showed the air pressure in kilopascals (kPa). She worked slowly so the air stayed at room temperature, 22 °C.
Pressure (kPa)
Volume of air (mL)
100
60
150
40
200
30
300
20
She plans to graph the data with pressure on the horizontal (x) axis and volume on the vertical (y) axis.
Which set of points should the student plot, written as (x, y)?
Hint
The passage says which variable goes on the x-axis. The first number of each point is the x-value.
Step-by-step solution
Where the answer comes from: the student will graph "with pressure on the horizontal (x) axis and volume on the vertical (y) axis." The table pairs run from "| 100 | 60 |" to "| 300 | 20 |".
Step by step:
Each point is written (x, y) = (pressure, volume).
From the table: (100, 60), (150, 40), (200, 30), (300, 20).
Swapping the order, as in (60, 100), would put volume on the x-axis.
Pairing 100 kPa with 20 mL breaks the rows of the table apart.
Correct answer: C.
Check: each point should come from a single row of the table. (150, 40) does: 150 kPa and 40 mL are in the same row.
Tip: Translating a table into graph points means keeping each row together and putting the x-variable first.
Question 17 of 36
Squeezing Air in a Syringe
A student sealed the tip of a plastic syringe so that no air could get in or out. She pushed on the plunger with different forces and read the volume of trapped air from the scale on the syringe. A pressure gauge attached to the syringe showed the air pressure in kilopascals (kPa). She worked slowly so the air stayed at room temperature, 22 °C.
Pressure (kPa)
Volume of air (mL)
100
60
150
40
200
30
300
20
She plans to graph the data with pressure on the horizontal (x) axis and volume on the vertical (y) axis.
Which term best describes the role of the air temperature (22 °C) in this experiment?
Hint
Did the student change the temperature on purpose, measure it as a result, or keep it the same?
Step-by-step solution
Where the answer comes from: "She worked slowly so the air stayed at room temperature, 22 °C."
Step by step:
The student changed the pressure on purpose (independent variable).
She measured the volume (dependent variable).
She worked slowly so the temperature stayed the same. A factor kept the same so it cannot affect the results is a controlled variable.
A hypothesis is a testable prediction, not a variable.
Correct answer: D.
Check: if temperature had changed, the air volume could have changed for that reason too, and the student could not tell which factor caused the change. Keeping it constant prevents that.
Tip: Look for phrases like "kept the same," "stayed at" or "the same for every trial". They signal controlled variables.
Question 18 of 36
Ramp Height and a Rolling Toy Car
A student tested how the height of a ramp affects how far a toy car rolls across the floor after leaving the ramp. She used the same car, the same ramp board and the same smooth tile floor for every trial. For each height, she released the car from the top of the ramp three times and averaged the distances.
Ramp height (cm)
Average distance rolled (cm)
10
55
20
110
30
160
40
215
The student sketched four graphs of her data.
Which graph correctly shows the data in the table, with ramp height on the horizontal axis?
Hint
Check each graph two ways: is ramp height on the horizontal axis, and does every point match a row of the table?
Step-by-step solution
Where the answer comes from: the table pairs "| 10 | 55 |", "| 20 | 110 |", "| 30 | 160 |" and "| 40 | 215 |" (ramp height in cm, distance in cm).
Step by step:
Graph A has the right axes, but its line falls: it puts 215 cm at 10 cm height. The values are reversed.
Graph B has ramp height across the bottom and distance up the side, with points (10, 55), (20, 110), (30, 160) and (40, 215). Every point matches. ✓
Graph C plots the 30-cm point at 110 cm instead of 160 cm.
Graph D has the right pairs but puts distance on the horizontal axis, which the question rules out.
Correct answer: B.
Check: ramp height is what the student changed (the independent variable), so by convention it belongs on the horizontal axis, which the question also requires.
Tip: To check a graph against a table, test one or two points exactly, and look for reversed trends and swapped axes.
Question 19 of 36
How Often Earthquakes Happen
Seismologists sort earthquakes by magnitude, a number that describes how much energy an earthquake releases. The table shows the average number of earthquakes recorded worldwide each year in four magnitude ranges, based on many years of records.
Magnitude range
Average number per year
5.0–5.9
1,300
6.0–6.9
130
7.0–7.9
15
8.0 and higher
1
Each step up of 1.0 in magnitude means an earthquake releases about 32 times as much energy.
A news writer wants one sentence that sums up the earthquake table accurately. Which sentence should the writer use?
Hint
Compare neighboring rows. Is each count about a fixed amount smaller, or about a fixed fraction of the one before?
Step-by-step solution
Where the answer comes from: the table gives "| 5.0–5.9 | 1,300 |", "| 6.0–6.9 | 130 |", "| 7.0–7.9 | 15 |" and "| 8.0 and higher | 1 |".
Step by step:
Divide each count by the next one: 1{,}300 \div 130 = 10; 130 \div 15 \approx 8.7; 15 \div 1 = 15.
Each step up has roughly one-tenth as many earthquakes as the range below it.
Subtracting gives very different differences (1,170, then 115, then 14), so "decreases by about 130 each step" is wrong.
Stronger earthquakes are much less common, and only about 1 earthquake of magnitude 8.0 or higher happens per year.
Correct answer: B.
Check: start at 1,300 and take one-tenth three times: 130, 13, 1.3. These are close to the table values of 130, 15 and 1.
Tip: When numbers shrink very fast, describe the pattern with a ratio ("one-tenth as many") rather than a fixed difference.
Question 20 of 36
Drop-downAn Energy Pyramid for a Grassland
An energy pyramid is a model that shows how energy moves through the feeding levels of an ecosystem. Each level is drawn on top of the level it eats. The pyramid shows a grassland food chain, with the energy available at each level in kilocalories (kcal) per square meter per year.
The same food chain can be written with arrows:
grass → grasshoppers → frogs → snakes → hawks
Scientists name the levels this way:
Producers make their own food from sunlight.
Primary consumers eat producers.
Secondary consumers eat primary consumers.
Tertiary consumers eat secondary consumers, and so on up the chain.
At each level, most of the energy is used for living (moving, growing, staying warm) or is lost as heat. Only about 10% is passed to the next level up.
Complete the summary of the energy pyramid.
The snakes receive kcal per square meter per year. Compared with the energy of the level directly below it, the energy of each level is about .
Choose an answer from each menu.
Hint
Read the snakes level on the pyramid. Then divide one level's energy by the level below it.
Step-by-step solution
Where the answer comes from: the pyramid shows grass 20,000, grasshoppers 2,000, frogs 200, snakes 20 and hawks 2 kcal per square meter per year. The passage adds: "Only about 10% is passed to the next level up."
Step by step:
The snakes level is labeled 20 kcal.
Compare each level with the level below: 2{,}000 \div 20{,}000 = 0.1, 200 \div 2{,}000 = 0.1, 20 \div 200 = 0.1.
0.1 is one-tenth (10%).
Correct answers: b1 = 20; b2 = one-tenth.
Check: going down the pyramid, each level has 10 times as much energy as the one above. That is the same fact seen from the other direction, so "ten times as much" describes a level compared with the one above it, not below.
Tip: When completing a written summary of a model, read the exact value for each blank and check that your ratio is in the direction the sentence asks for.
Question 21 of 36
Respiration and Photosynthesis
Plants and animals both release energy from food through a process called cellular respiration. In cellular respiration, a cell combines glucose (a sugar) with oxygen. The reaction produces carbon dioxide and water and releases energy that the cell can use. For each molecule of glucose used, six molecules of oxygen are used, and six molecules of carbon dioxide and six molecules of water are made.
Plants also carry out photosynthesis, which uses light energy to make glucose. Photosynthesis is summarized by this equation:
Which equation correctly represents cellular respiration as it is described in the passage?
Hint
Find the reactants (what is combined) and products (what is made) in the first paragraph, and check the numbers of molecules.
Step-by-step solution
Where the answer comes from: the passage says "a cell combines glucose (a sugar) with oxygen", the reaction "produces carbon dioxide and water and releases energy", and "six molecules of oxygen are used, and six molecules of carbon dioxide and six molecules of water are made."
Step by step:
Reactants (left side): glucose, \text{C}_6\text{H}_{12}\text{O}_6, and oxygen, 6\text{O}_2.
Products (right side): 6\text{CO}_2, 6\text{H}_2\text{O} and energy.
Only one choice has these reactants, products and coefficients.
The equation with carbon dioxide and water on the left is photosynthesis, the reverse process.
Correct answer: A.
Check: count atoms. Left: C 6; H 12; O 6 + 12 = 18. Right: C 6; H 12; O 12 + 6 = 18. Balanced.
Tip: To turn words into an equation, list reactants and products separately first, then add coefficients from the numbers given.
Question 22 of 36
Respiration and Photosynthesis
Plants and animals both release energy from food through a process called cellular respiration. In cellular respiration, a cell combines glucose (a sugar) with oxygen. The reaction produces carbon dioxide and water and releases energy that the cell can use. For each molecule of glucose used, six molecules of oxygen are used, and six molecules of carbon dioxide and six molecules of water are made.
Plants also carry out photosynthesis, which uses light energy to make glucose. Photosynthesis is summarized by this equation:
Which statement correctly describes the photosynthesis equation in words?
Hint
The coefficient (big number in front) counts molecules. The subscript (small number) counts atoms inside one molecule.
Step-by-step solution
Where the answer comes from: the passage gives the equation 6\text{CO}_2 + 6\text{H}_2\text{O} + \text{light energy} \rightarrow \text{C}_6\text{H}_{12}\text{O}_6 + 6\text{O}_2.
Step by step:
Left of the arrow (reactants): 6 molecules of carbon dioxide and 6 molecules of water, plus light energy.
Right of the arrow (products): 1 molecule of glucose (no coefficient means 1) and 6 molecules of oxygen.
6\text{O}_2 means six molecules, each made of two oxygen atoms.
The arrow points from reactants to products, so glucose is made, not used.
Correct answer: D.
Check: read the equation aloud: "six C-O-two plus six H-two-O, with light, yields one glucose plus six O-two." That matches the correct statement.
Tip: Translate an equation in three parts: what goes in, what comes out, and how many of each (coefficients).
Question 23 of 36
Drag and dropRespiration and Photosynthesis
Plants and animals both release energy from food through a process called cellular respiration. In cellular respiration, a cell combines glucose (a sugar) with oxygen. The reaction produces carbon dioxide and water and releases energy that the cell can use. For each molecule of glucose used, six molecules of oxygen are used, and six molecules of carbon dioxide and six molecules of water are made.
Plants also carry out photosynthesis, which uses light energy to make glucose. Photosynthesis is summarized by this equation:
Use the description of cellular respiration in the passage. Drag each item into the correct column. One item will not be used.
Reactants (used up)
Products (made)
Tap a tile, then tap a box to place it.
Hint
Reactants are what the cell combines. Products are what the reaction makes or releases.
Step-by-step solution
Where the answer comes from: the passage says "a cell combines glucose (a sugar) with oxygen" and the reaction "produces carbon dioxide and water and releases energy that the cell can use."
Step by step:
Reactants are combined and used up: glucose and oxygen.
Products are made or released: carbon dioxide, water and usable energy for the cell.
Light energy belongs to photosynthesis, not cellular respiration, so it is the unused item.
Check: respiration and photosynthesis are reverses of each other. The products of photosynthesis (glucose, oxygen) should be the reactants of respiration, and they are.
Tip: When organizing text into a table, underline the action words ("combines," "produces," "releases"). They tell you which column each item belongs in.
Question 24 of 36
Sea Level at a Harbor
A tide gauge measures the height of the ocean surface at one harbor. Scientists averaged each year's readings and compared them with the 1990 average. The table shows how much higher the yearly average sea level was than in 1990.
Year
Rise in sea level since 1990 (mm)
1990
0
2000
30
2010
65
2020
110
Local sea level can change because ocean water expands as it warms, because melting glaciers and ice sheets add water to the ocean, and because land along some coasts slowly sinks or rises.
A student made four sketches of the tide-gauge data.
Only one sketch has both the correct units and the correct values. Which one?
Hint
Check the axis label and unit first, then compare each plotted value with the table.
Step-by-step solution
Where the answer comes from: the table header is "| Year | Rise in sea level since 1990 (mm) |", and it includes "| 2010 | 65 |" and "| 2020 | 110 |" (with 0 in 1990 and 30 in 2000).
Step by step:
Graph A has the right numbers, but its axis says centimeters (cm). 110 cm would be ten times the real rise of 110 mm.
Graph B plots 2010 at 45 mm instead of 65 mm.
Graph C uses millimeters and plots 0, 30, 65 and 110 at the right years. ✓
Graph D has the line falling from 110 to 0, which reverses the data.
Correct answer: C.
Check: two things must both be right: the units on the axis and every plotted point. Only Graph C passes both.
Tip: Wrong units are an easy trap because the numbers look correct. Always read the axis labels before you look at the line.
Question 25 of 36
Reading the Layers of a Cliff
A geologist studied a cliff where flat layers of sedimentary rock are exposed. Her field notes say:
The shale lies directly on top of the limestone. The sandstone is the top layer of the cliff. The conglomerate, a rock made of rounded pebbles cemented together, lies directly below the limestone and is the bottom layer I can see. A layer of coal lies between the sandstone and the shale.
In undisturbed layers of sedimentary rock, each layer formed on top of the layers that were already there. So the deepest layer is the oldest, and the top layer is the youngest. This idea is called the law of superposition.
Which list correctly shows the rock layers from top to bottom, as described in the field notes?
Hint
Start with the layers whose positions are fixed (top and bottom), then place the others using "directly on top of" and "between."
Step-by-step solution
Where the answer comes from: the notes say "The sandstone is the top layer of the cliff.", the conglomerate "lies directly below the limestone and is the bottom layer I can see", "The shale lies directly on top of the limestone." and "A layer of coal lies between the sandstone and the shale."
Step by step:
Top: sandstone. Bottom: conglomerate.
Limestone is directly above the conglomerate (second from the bottom).
Shale is directly on top of the limestone (third from the bottom).
Coal is between the sandstone and the shale (second from the top).
Top to bottom: sandstone, coal, shale, limestone, conglomerate.
Correct answer: B.
Check: re-read each sentence of the notes against your list. Every statement is true for this order, and for no other order.
Tip: When you turn a written description into a diagram or list, place the fixed items first and fill in the rest with the relationship words.
Question 26 of 36
Water Temperature and Dissolved Oxygen
Fish and other water animals breathe oxygen that is dissolved in water. A student wanted to know how water temperature affects the greatest amount of oxygen that fresh water can hold. She used published reference values and organized them in a table.
Water temperature (°C)
Dissolved oxygen (mg/L)
0
14.6
10
11.3
20
9.1
30
7.6
(mg/L = milligrams of oxygen per liter of water.) She now wants to present the data as a graph and describe the results in her report.
The student drew four possible graphs of her data.
Which graph best represents the data in the table?
Hint
Check three things for each graph: is it the right kind of graph, is each variable on the proper axis, and do the values match the table?
Step-by-step solution
Where the answer comes from: the table pairs 0 °C → 14.6, 10 °C → 11.3, 20 °C → 9.1 and 30 °C → 7.6 mg/L. The student chose the temperatures, so temperature is the independent variable; dissolved oxygen is the dependent variable.
Step by step:
Graph A plots the right values, but puts temperature (the independent variable) on the vertical axis. The convention is independent variable on the horizontal (x) axis, so A is not the best choice.
Graph B is a circle graph. The four oxygen values are not parts of a whole, so slices are meaningless.
Graph C puts temperature on the x-axis and dissolved oxygen on the y-axis, and the line falls from 14.6 to 7.6 — matching the table. ✓
Graph D has the right axes, but the line rises, which reverses the data (it shows 7.6 mg/L at 0 °C).
Correct answer: C.
Tip: For a graph to be "best," it must be the right type, have the independent variable on the x-axis, and plot the values exactly as given. Check the direction of the line against two table rows.
Question 27 of 36
Water Temperature and Dissolved Oxygen
Fish and other water animals breathe oxygen that is dissolved in water. A student wanted to know how water temperature affects the greatest amount of oxygen that fresh water can hold. She used published reference values and organized them in a table.
Water temperature (°C)
Dissolved oxygen (mg/L)
0
14.6
10
11.3
20
9.1
30
7.6
(mg/L = milligrams of oxygen per liter of water.) She now wants to present the data as a graph and describe the results in her report.
Which statement uses scientific vocabulary correctly to describe the student's data?
Hint
Decide whether the two variables move in the same direction or opposite directions, and which variable was chosen by the student.
Step-by-step solution
Where the answer comes from: the table shows that as water temperature goes up (0 → 10 → 20 → 30 °C), dissolved oxygen goes down (14.6 → 11.3 → 9.1 → 7.6 mg/L).
Step by step:
When one variable increases as the other decreases, the relationship is inverse (also called negative).
So A is correct: dissolved oxygen has an inverse relationship with temperature.
B says "direct (positive)," which would mean both increase together — the opposite of the data.
C swaps the variables: temperature is the variable the student chose (independent); oxygen depends on it (dependent).
D claims cold water produces oxygen. The data show how much oxygen water can hold (dissolve); nothing in the table shows oxygen being produced.
Correct answer: A.
Tip: Learn the pairs: direct/positive = both go up together; inverse/negative = one goes up as the other goes down. "Independent" is what is chosen or changed; "dependent" is what is measured.
Question 28 of 36
Select allWater Temperature and Dissolved Oxygen
Fish and other water animals breathe oxygen that is dissolved in water. A student wanted to know how water temperature affects the greatest amount of oxygen that fresh water can hold. She used published reference values and organized them in a table.
Water temperature (°C)
Dissolved oxygen (mg/L)
0
14.6
10
11.3
20
9.1
30
7.6
(mg/L = milligrams of oxygen per liter of water.) She now wants to present the data as a graph and describe the results in her report.
Select all statements that are accurate descriptions of the data in the table.
Select all that apply.
Hint
Compute the change for each 10 °C step before judging statements about "the same amount" or "larger."
Step-by-step solution
Where the answer comes from: the table: 0 °C → 14.6, 10 °C → 11.3, 20 °C → 9.1, 30 °C → 7.6 mg/L.
Step by step:
Changes for each 10 °C step: 14.6 - 11.3 = 3.3; 11.3 - 9.1 = 2.2; 9.1 - 7.6 = 1.5 mg/L.
A — accurate. Every step is a decrease, so oxygen decreases as temperature increases.
B — not accurate. The drops are 3.3, 2.2 and 1.5, not equal. The relationship is not linear; the line on a graph would curve and flatten.
C — accurate. The drop from 0 to 10 °C (3.3 mg/L) is larger than the drop from 20 to 30 °C (1.5 mg/L).
D — not accurate. 40 °C was not tested, and the trend is downward; extending it would predict less oxygen, not more.
E — not accurate. The table gives oxygen amounts only. It says nothing about fish dying at any temperature.
Correct answers: A and C.
Tip: Accurate descriptions stay within the data. Calculate the step-by-step changes to test words like "same," "steady," "faster" and "slower."
Question 29 of 36
Burning Natural Gas
Natural gas, used in many home stoves and furnaces, is mostly methane, \text{CH}_4. When methane burns, each methane molecule reacts with two molecules of oxygen gas, \text{O}_2, from the air. The reaction produces one molecule of carbon dioxide, \text{CO}_2, and two molecules of water vapor, \text{H}_2\text{O}, and it releases heat.
If a burner does not get enough oxygen, some of the carbon forms carbon monoxide, \text{CO}, instead. Carbon monoxide is a colorless, odorless, poisonous gas, which is why homes with gas appliances should have carbon monoxide detectors.
In a chemical equation, the number in front of a formula (the coefficient) tells how many molecules take part. The small number after an element's symbol (the subscript) tells how many atoms of that element are in one molecule. A balanced equation has the same number of each kind of atom on both sides.
Which equation correctly shows the burning of methane, as described in the first paragraph?
Hint
Write down how many molecules of each substance the passage names, then check that the equation is balanced.
Step-by-step solution
Where the answer comes from: "each methane molecule reacts with two molecules of oxygen gas" and the reaction "produces one molecule of carbon dioxide" and "two molecules of water vapor."
Step by step:
Reactants: \text{CH}_4 + 2\text{O}_2.
Products: \text{CO}_2 + 2\text{H}_2\text{O}.
Count atoms. Left: C 1, H 4, O 4. Right: C 1, H 2 \times 2 = 4, O 2 + 2 = 4. Balanced.
The choice with carbon monoxide describes burning with too little oxygen, and its oxygen atoms do not balance (4 on the left, 3 on the right).
Correct answer: C.
Check: the choice without coefficients has 2 O atoms on the left but 3 on the right, so it breaks the rule that a balanced equation has the same atoms on both sides.
Tip: Turn each phrase into symbols ("two molecules of oxygen" = 2\text{O}_2), then count every kind of atom on both sides.
Question 30 of 36
Voltage and Current in a Simple Circuit
A student built a simple circuit with a battery pack, a 10-ohm (Ω) resistor and an ammeter, a meter that measures electric current in amperes (A). She changed the voltage of the battery pack and recorded the current each time. The resistor stayed the same.
Voltage (V)
Current (A)
1.5
0.15
3.0
0.30
4.5
0.45
6.0
0.60
Her teacher explained a rule called Ohm's law: the current through a resistor equals the voltage across it divided by the resistance. So with a larger resistance, the same voltage pushes less current through the circuit.
Which statement correctly uses the terms directly proportional and inverse to describe the circuit results and Ohm's law?
Hint
Directly proportional: both go up together by the same factor. Inverse: one goes up as the other goes down.
Step-by-step solution
Where the answer comes from: the table shows "| 1.5 | 0.15 |" and "| 3.0 | 0.30 |" with the same 10-Ω resistor, and the teacher says "So with a larger resistance, the same voltage pushes less current through the circuit."
Step by step:
Doubling the voltage from 1.5 V to 3.0 V doubles the current from 0.15 A to 0.30 A. Same factor, both rising: directly proportional.
With voltage held the same, a larger resistance gives less current. One goes up, the other goes down: an inverse relationship.
So current is directly proportional to voltage (resistance constant) and inversely related to resistance (voltage constant).
Correct answer: A.
Check:I = \dfrac{V}{R}: V is on top (bigger V, bigger I), and R is on the bottom (bigger R, smaller I).
Tip: In a formula, a variable on top of a fraction is directly related to the result; a variable on the bottom is inversely related.
Question 31 of 36
Select allHow Often Earthquakes Happen
Seismologists sort earthquakes by magnitude, a number that describes how much energy an earthquake releases. The table shows the average number of earthquakes recorded worldwide each year in four magnitude ranges, based on many years of records.
Magnitude range
Average number per year
5.0–5.9
1,300
6.0–6.9
130
7.0–7.9
15
8.0 and higher
1
Each step up of 1.0 in magnitude means an earthquake releases about 32 times as much energy.
Select all the statements that accurately describe the information in the passage.
Select all that apply.
Hint
Check each statement with a quick calculation. For energy, remember the factor is multiplied for each step of 1.0.
Step-by-step solution
Where the answer comes from: the table ("| 5.0–5.9 | 1,300 |", "| 6.0–6.9 | 130 |", "| 7.0–7.9 | 15 |") and the sentence "Each step up of 1.0 in magnitude means an earthquake releases about 32 times as much energy."
Step by step:
A — accurate.1{,}300 \div 130 = 10, so magnitude 5 earthquakes are about 10 times as common.
B — accurate. The table gives 15 per year for 7.0–7.9.
C — not accurate. From 6.0 to 8.0 is two steps: 32 \times 32 = 1{,}024, about 1,000 times as much energy, not 2 times.
D — accurate. One step from 6.0 to 7.0 means about 32 times as much energy.
E — not accurate. Magnitude 6.0 or higher: 130 + 15 + 1 = 146 out of 1{,}300 + 146 = 1{,}446, about 10%, not more than half.
Correct answers: A, B and D.
Check: for multi-step energy questions, multiply the factor once per step; never add the steps.
Tip: In select-all questions, verify each statement on its own with the data; numbers that look familiar can still be used the wrong way.
Question 32 of 36
Burning Natural Gas
Natural gas, used in many home stoves and furnaces, is mostly methane, \text{CH}_4. When methane burns, each methane molecule reacts with two molecules of oxygen gas, \text{O}_2, from the air. The reaction produces one molecule of carbon dioxide, \text{CO}_2, and two molecules of water vapor, \text{H}_2\text{O}, and it releases heat.
If a burner does not get enough oxygen, some of the carbon forms carbon monoxide, \text{CO}, instead. Carbon monoxide is a colorless, odorless, poisonous gas, which is why homes with gas appliances should have carbon monoxide detectors.
In a chemical equation, the number in front of a formula (the coefficient) tells how many molecules take part. The small number after an element's symbol (the subscript) tells how many atoms of that element are in one molecule. A balanced equation has the same number of each kind of atom on both sides.
Propane, \text{C}_3\text{H}_8, is another fuel. Its burning is shown by this equation:
Which statement correctly describes this equation in words?
Hint
Use the passage's definitions: coefficients count molecules; subscripts count atoms in one molecule.
Step-by-step solution
Where the answer comes from: the passage explains that "the number in front of a formula (the coefficient) tells how many molecules take part" and "The small number after an element's symbol (the subscript) tells how many atoms of that element are in one molecule."
Step by step:
\text{C}_3\text{H}_8 has no coefficient, so 1 molecule; its subscripts mean 3 carbon atoms and 8 hydrogen atoms.
5\text{O}_2 = 5 molecules of oxygen.
Products: 3\text{CO}_2 = 3 molecules of carbon dioxide; 4\text{H}_2\text{O} = 4 molecules of water.
Is it balanced? Oxygen atoms: left 5 \times 2 = 10; right 3 \times 2 + 4 \times 1 = 10. Carbon 3 = 3; hydrogen 8 = 4 \times 2. Yes.
Correct answer: B.
Check: "three molecules of propane" would need a 3 in front of \text{C}_3\text{H}_8; the 3 is a subscript, so it counts carbon atoms, not molecules.
Tip: Before you judge whether an equation is balanced, multiply each subscript by its coefficient and add up both sides.
Question 33 of 36
Voltage and Current in a Simple Circuit
A student built a simple circuit with a battery pack, a 10-ohm (Ω) resistor and an ammeter, a meter that measures electric current in amperes (A). She changed the voltage of the battery pack and recorded the current each time. The resistor stayed the same.
Voltage (V)
Current (A)
1.5
0.15
3.0
0.30
4.5
0.45
6.0
0.60
Her teacher explained a rule called Ohm's law: the current through a resistor equals the voltage across it divided by the resistance. So with a larger resistance, the same voltage pushes less current through the circuit.
Which equation expresses Ohm's law as the teacher stated it? (I = current, V = voltage, R = resistance)
Hint
Translate the sentence word by word: "equals" is =, "divided by" is a fraction bar. Then test with a row of the table.
Step-by-step solution
Where the answer comes from: the teacher said "the current through a resistor equals the voltage across it divided by the resistance."
Step by step:
"The current" → I; "equals" → =.
"the voltage … divided by the resistance" → \dfrac{V}{R}.
So I = \dfrac{V}{R}.
Test with the table row "| 3.0 | 0.30 |": \dfrac{3.0}{10} = 0.30 A. It matches.
Correct answer: D.
Check: test a wrong choice: I = V \times R gives 3.0 \times 10 = 30 A, which is 100 times the measured 0.30 A.
Tip: When you translate words into a formula, always check it with one row of real data. A wrong formula fails right away.
Question 34 of 36
Select allSea Level at a Harbor
A tide gauge measures the height of the ocean surface at one harbor. Scientists averaged each year's readings and compared them with the 1990 average. The table shows how much higher the yearly average sea level was than in 1990.
Year
Rise in sea level since 1990 (mm)
1990
0
2000
30
2010
65
2020
110
Local sea level can change because ocean water expands as it warms, because melting glaciers and ice sheets add water to the ocean, and because land along some coasts slowly sinks or rises.
Select all the statements that accurately describe the tide-gauge data.
Select all that apply.
Hint
Find the rise in each decade. Also ask whether the table itself shows what caused the rise.
Step-by-step solution
Where the answer comes from: the table gives 0 mm (1990), "| 2000 | 30 |", "| 2010 | 65 |" and "| 2020 | 110 |". The passage lists several possible causes: "Local sea level can change because ocean water expands as it warms", melting ice and sinking or rising land.
Step by step:
Rise per decade: 30 - 0 = 30 mm, 65 - 30 = 35 mm, 110 - 65 = 45 mm.
A — accurate. Sea level rose in every decade.
B — accurate. 45 mm (2010–2020) is more than 30 mm (1990–2000), so the rise got faster.
C — not accurate. 30, 35 and 45 mm are not the same amount.
D — accurate. The 2020 value is 110 mm above 1990.
E — not accurate. The table shows how much sea level rose, not why. The passage names three possible causes, and the data do not separate them.
Correct answers: A, B and D.
Check: for any "the data show that X caused Y" statement, ask whether the data measured X at all. Here they did not.
Tip: Accurate descriptions stick to what was measured. Statements about causes need evidence the table does not give.
Question 35 of 36
Drop-downSqueezing Air in a Syringe
A student sealed the tip of a plastic syringe so that no air could get in or out. She pushed on the plunger with different forces and read the volume of trapped air from the scale on the syringe. A pressure gauge attached to the syringe showed the air pressure in kilopascals (kPa). She worked slowly so the air stayed at room temperature, 22 °C.
Pressure (kPa)
Volume of air (mL)
100
60
150
40
200
30
300
20
She plans to graph the data with pressure on the horizontal (x) axis and volume on the vertical (y) axis.
Complete the summary of the student's results.
When the pressure doubled from 100 kPa to 200 kPa, the volume of air . This shows that, at constant temperature, the volume of a gas is its pressure.
Choose an answer from each menu.
Hint
Compare the volumes at 100 kPa and 200 kPa. Then check the pattern with 150 kPa and 300 kPa.
Step-by-step solution
Where the answer comes from: the table gives "| 100 | 60 |" and "| 200 | 30 |", and also "| 150 | 40 |" and "| 300 | 20 |".
Step by step:
From 100 kPa to 200 kPa (pressure doubled), the volume went from 60 mL to 30 mL: it was cut in half.
Check another pair: 150 kPa to 300 kPa (doubled), volume 40 mL to 20 mL (halved). Same pattern.
When one variable doubles and the other halves, so their product is constant, the relationship is inversely proportional.
Correct answers: b1 = was cut in half; b2 = inversely proportional to.
Check: a directly proportional relationship would show volume doubling when pressure doubled, which is the opposite of the data.
Tip: A constant product (x \times y = same number) means inverse proportion; a constant ratio (y \div x = same number) means direct proportion.
Question 36 of 36
Drag and dropReading the Layers of a Cliff
A geologist studied a cliff where flat layers of sedimentary rock are exposed. Her field notes say:
The shale lies directly on top of the limestone. The sandstone is the top layer of the cliff. The conglomerate, a rock made of rounded pebbles cemented together, lies directly below the limestone and is the bottom layer I can see. A layer of coal lies between the sandstone and the shale.
In undisturbed layers of sedimentary rock, each layer formed on top of the layers that were already there. So the deepest layer is the oldest, and the top layer is the youngest. This idea is called the law of superposition.
Use the field notes and the law of superposition. Drag each rock layer into order from oldest (1) to youngest (5). One item will not be used.
1 (oldest)
2
3
4
5 (youngest)
Tap a tile, then tap a box to place it.
Hint
First put the layers in order from top to bottom. Then decide which end is the oldest.
Step-by-step solution
Where the answer comes from: the law of superposition: "So the deepest layer is the oldest, and the top layer is the youngest." The notes give "The sandstone is the top layer of the cliff." and say the conglomerate "lies directly below the limestone and is the bottom layer I can see."
Step by step:
From the notes, top to bottom: sandstone, coal, shale, limestone, conglomerate.
The deepest layer is the oldest, so reverse the list to go from oldest to youngest.
Check: the youngest layer (5) must be the top layer, sandstone, and the oldest (1) must be the bottom layer, conglomerate. Both ends match.
Tip: Sequencing questions often need two steps: first organize the information from the text, then apply a rule (here, superposition) to put it in the asked-for order.
