Math Mixed Practice Test 3

Question 1 of 20 · Scatter plots and two-variable data

A tech reviewer tested 10 phones of the same model. The scatter plot shows how many hours each phone was used and the percent of battery remaining. A trend line has been drawn.

Scatter plot of hours of phone use (0 to 12) versus battery remaining in percent (0 to 100) for 10 phones, with a dashed trend line from (0, 100) to (12, 4) that passes through (5, 60) and (10, 20). Points: (1, 90), (2, 86), (3, 74), (4, 70), (5, 62), (6, 50), (7, 46), (9, 30), (10, 18), (11, 14).0204060801000123456789101112Hours of useBattery remaining (%)

Let x be the hours of use and y the percent of battery remaining. Which equation best represents the trend line?

Answer choices
Hint

Find where the line crosses the vertical axis, then use two clear points on the line to find the slope. Is the line going up or down?

Question 2 of 20 · Scale factors and scale drawings

A rectangular store sign has an area of 18 square feet. The owner orders a new sign with the same shape, but every length is 2.5 times as long. What is the area of the new sign?

Answer choices
Hint

Both the length and the width are multiplied by 2.5. What does that do to length × width?

Question 3 of 20 · Evaluate polynomials

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Find 6x^2 - 5x + 1 for x = \tfrac{1}{2}. Enter your answer as a number.

Type your answer in the box. Fractions like 3/4 are fine.

Hint

Square the fraction first: \left(\tfrac{1}{2}\right)^2 = \tfrac{1}{4}. You may switch to decimals: \tfrac{1}{2} = 0.5.

Question 4 of 20 · Rectangular prisms

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A closed jewelry box is a rectangular prism 9\text{ cm} long, 5\text{ cm} wide and 4\text{ cm} tall. Dana wants to cover the whole outside of the box with fabric, with no overlap.

How many square centimeters of fabric does she need?

\text{cm}^2

Type your answer in the box. Fractions like 3/4 are fine.

Hint

Covering the outside means all 6 faces. Use SA = ph + 2B, or add the three different face areas and double the total.

Question 5 of 20 · Rules of exponents

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Write the value of \dfrac{10^{9}}{10^{6}} as a whole number.

Type your answer in the box. Fractions like 3/4 are fine.

Hint

Both powers have the same base, 10. What do you do with the exponents when you divide?

Question 6 of 20 · Proportions and unit conversion

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A bag of dog treats weighs 3.5 pounds. How much does the bag weigh in ounces? (1 pound = 16 ounces)

ounces

Type your answer in the box. Fractions like 3/4 are fine.

Hint

An ounce is smaller than a pound. Will the number of ounces be bigger or smaller than 3.5?

Question 7 of 20 · Identify functions

No calculatorDrag and drop

The tiles mix equations, word descriptions, ordered pairs and a graph description. Sort them: is y (the output) a function of x (the input)? Three tiles belong in each box.

FunctionNot a function

Tap a tile, then tap a box to place it.

Hint

For each tile, try to find one input that could have two different outputs.

Question 8 of 20 · Compare proportional relationships

Two lemonade recipes mix lemon juice and water in proportional amounts.

  • Recipe A: j = \tfrac{3}{8}w, where j is cups of lemon juice and w is cups of water.
  • Recipe B: shown in the table.
Water (w, cups)410
Lemon juice (j, cups)1.53.75

The recipe with more lemon juice per cup of water tastes stronger. Which statement is true?

Answer choices
Hint

Write both unit rates (cups of juice per 1 cup of water) as decimals.

Question 9 of 20 · Parallel and perpendicular lines

Which equation represents the line that is parallel to y = -\tfrac{1}{2}x + 3 and passes through the point (4, 5)?

Answer choices
Hint

Use the same slope as the given line. Then substitute (4, 5) to find a new y-intercept.

Question 10 of 20 · Unit rate as slope

Select all

Select all the relationships that are proportional with a constant of proportionality of 2.5.

Select all that apply.

Answer choices
Hint

For each one, check two things: is it proportional (through the origin, constant \frac{y}{x})? Is \frac{y}{x} equal to 2.5?

Question 11 of 20 · Slope from a graph, equation or table

What is the slope of the line 4x + 2y = 10?

Answer choices
Hint

Get y by itself first. Then read the coefficient of x.

Question 12 of 20 · Right prisms

A livestock water trough is a triangular prism with V-shaped ends, as shown.

Water trough shaped like a triangular prism with a V-shaped end: the top of each triangular end is 2 feet wide and the trough is 1.5 feet deep; the trough is 10 feet long. 2 ft 1.5 ft 10 ft

One cubic foot holds about 7.5 gallons. About how many gallons does the trough hold when full?

Answer choices
Hint

Find the volume in cubic feet first (triangle area × length), then convert to gallons.

Question 13 of 20 · Mean, median, mode, range, weighted average

On a reading test, the 20 students in Class A had a mean score of 78. The 30 students in Class B had a mean score of 88. What is the mean score of all 50 students together?

Answer choices
Hint

The two classes are different sizes, so you cannot just average 78 and 88. Find each class's total points first.

Question 14 of 20 · Composite 2-D figures

No calculatorSelect all
L-shaped figure: left side 9 ft, bottom 12 ft, right side 5 ft, top 7 ft, with a cut-out corner at the top right whose vertical edge is 4 ft and horizontal edge is 5 ft 7 ft 4 ft 5 ft 5 ft 12 ft 9 ft

Select all of the expressions that give the area, in square feet, of the L-shaped figure.

Select all that apply.

Answer choices
Hint

Try different ways to cut the figure: a vertical cut, a horizontal cut, or the full rectangle minus the missing corner. Evaluate each expression to compare.

Question 15 of 20 · Triangles and rectangles: area and perimeter

A farmer fences a rectangular pasture that is 120 feet long and 85 feet wide. Fencing costs $4.50 per foot.

What is the total cost to fence all four sides?

Answer choices
Hint

Find how many feet of fence are needed first. Then think about what one foot costs.

Question 16 of 20 · Write polynomial expressions from context

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A farmer is building a rectangular pen against the side of a barn, as shown. The barn forms one side, so no fence is needed there. Each side touching the barn is x feet, and the side opposite the barn is (3x - 4) feet.

A rectangular pen built against a barn wall. The barn forms the top side, with no fence. The two sides touching the barn are each x feet long and the side opposite the barn is (3x − 4) feet long; these three sides are fenced.BARNpenxx3x − 4fence shown in blue; the barn wall needs no fence

Write an expression for the total length of fence. How many feet of fence are needed when x = 12?

ft

Type your answer in the box. Fractions like 3/4 are fine.

Hint

Only three sides need fence. Add their lengths, combine like terms, and then substitute.

Question 17 of 20 · Solve linear inequalities

No calculator

Find all numbers x for which \dfrac{x}{-5} < 3.

Answer choices
Hint

x is divided by -5. What is the opposite operation, and what does it do to the inequality sign?

Question 18 of 20 · Parallel and perpendicular lines

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What is the slope of a line that is perpendicular to the line 5x - 2y = 8? Enter your answer as a decimal or a fraction.

Type your answer in the box. Fractions like 3/4 are fine.

Hint

Solve 5x - 2y = 8 for y to find its slope. Then flip and switch.

Question 19 of 20 · Solve quadratic equations

No calculator

Factor to solve. Which pair of numbers is the complete solution set of x^2 - 9x + 20 = 0?

Answer choices
Hint

Look for two numbers that multiply to 20 and add to -9.

Question 20 of 20 · Rational expression operations

What is the simplest form of the fraction \dfrac{6 - 2x}{x - 3}? (Assume x does not equal 3.)

Answer choices
Hint

Factor -2 out of the numerator. Compare what is left with the denominator.

Formula sheet

Area

Area of a square s = length of a side
A = s^2
Area of a rectangle l = length, w = width
A = lw
Area of a parallelogram b = base, h = height (straight up from the base, not the slanted side)
A = bh
Area of a triangle b = base, h = height
A = \tfrac{1}{2}bh
Area of a trapezoid b_1 and b_2 = the two parallel sides, h = height
A = \tfrac{1}{2}h(b_1 + b_2)
Area of a circle r = radius (half of the diameter); \pi \approx 3.14
A = \pi r^2

Perimeter and circumference

Perimeter of a square s = length of a side
P = 4s
Perimeter of a rectangle l = length, w = width
P = 2l + 2w
Perimeter of a triangle s_1, s_2, s_3 = the three side lengths
P = s_1 + s_2 + s_3
Circumference of a circle the distance around a circle; r = radius, d = diameter, \pi \approx 3.14
C = 2\pi r = \pi d

Surface area (SA) and volume (V)

p = perimeter of the base with area B; \pi \approx 3.14

Rectangular prism l = length, w = width, h = height
SA = 2lw + 2lh + 2wh \qquad V = lwh
Right prism B = area of the base, p = perimeter of the base, h = height
SA = ph + 2B \qquad V = Bh
Cylinder r = radius of the base, h = height
SA = 2\pi rh + 2\pi r^2 \qquad V = \pi r^2 h
Pyramid B = area of the base, p = perimeter of the base, s = slant height, h = height
SA = \tfrac{1}{2}ps + B \qquad V = \tfrac{1}{3}Bh
Cone r = radius of the base, s = slant height, h = height
SA = \pi rs + \pi r^2 \qquad V = \tfrac{1}{3}\pi r^2 h
Sphere r = radius
SA = 4\pi r^2 \qquad V = \tfrac{4}{3}\pi r^3

Data

Mean (average) add all the values of the data set, then divide by how many values there are
\text{mean} = \dfrac{\text{total of the values}}{\text{number of values}}
Median
the middle value when the data are in order; with an even number of values, it is the mean of the two middle values

Algebra

Slope of a line (x_1, y_1) and (x_2, y_2) = two points on the line
m = \dfrac{y_2 - y_1}{x_2 - x_1}
Slope-intercept form of a line m = slope, b = y-intercept (where the line crosses the y-axis)
y = mx + b
Point-slope form of a line m = slope, (x_1, y_1) = a point on the line
y - y_1 = m(x - x_1)
Standard form of a quadratic equation a, b, c are numbers and a \ne 0
y = ax^2 + bx + c
Quadratic formula solves ax^2 + bx + c = 0
x = \dfrac{-b \pm \sqrt{b^2 - 4ac}}{2a}
Pythagorean theorem in a right triangle: a, b = the two legs, c = the hypotenuse (the longest side, across from the right angle)
a^2 + b^2 = c^2
Simple interest I = interest, P = principal (the amount saved or borrowed), r = rate per year as a decimal, t = time in years
I = Prt
Distance = rate × time d = distance, r = rate (speed), t = time
d = rt
Total cost
\text{total cost} = (\text{number of units}) \times (\text{price per unit})