This free ACT math practice test contains 30 challenging questions with complete step-by-step solutions. Use these problems to prepare for the ACT mathematics section.
What is the greatest common factor (GCF) of 45, 135 and 270?
Use prime factorization:
\[ 45 = 1 \times 3^2 \times 5 \]
\[ 135 = 1 \times 3^3 \times 5 \]
\[ 270 = 1 \times 2 \times 3^3 \times 5 \]
The GCF \( = 5 \times 3^2 = 45 \)
What is the value of \( 2x + \frac{1}{2} \) when \( 5x - 3 = -3x + 5 \)?
Solve the equation:
\[ 5x + 3x = 5 + 3 \]
\[ 8x = 8 \]
\[ x = 1 \]
Now calculate:
\[ 2x + \frac{1}{2} = 2(1) + \frac{1}{2} = 2\frac{1}{2} \]
The width \( W \) of a rectangle is 2 inches less than half its length \( L \). Express the perimeter \( P \) of the rectangle in terms of the length \( L \).
Express width in terms of length:
\[ W = \frac{L}{2} - 2 \]
Perimeter formula:
\[ P = 2(W + L) = 2\left(\frac{L}{2} - 2 + L\right) = L - 4 + 2L = 3L - 4 \]
The total surface area of all six sides of the rectangular box below is equal to 80 square inches. What is the volume of the rectangular box in inches cubed?

Total surface area calculation:
Left and right sides: \( 4x + 4x = 8x \)
Front and back sides: \( 4x + 4x = 8x \)
Top and bottom sides: \( 16 + 16 = 32 \)
Total area: \( 16x + 32 = 80 \)
Solve for \( x \):
\[ 16x = 80 - 32 \]
\[ 16x = 48 \]
\[ x = 3 \text{ in} \]
Volume calculation:
\[ V = 4 \times 4 \times 3 = 48 \text{ inches}^3 \]
The points \( A(-4, -4) \), \( B(-1, -2) \) and \( C(x, -8) \) are the vertices of a right triangle with the right angle at \( (-1, -2) \). Find the value of \( x \).
Since the right angle is at point \( B \), \( BA \) and \( BC \) are perpendicular. Using distance formula:
\[ AB^2 = (-1 + 4)^2 + (-2 + 4)^2 = 13 \]
\[ BC^2 = (x + 1)^2 + (-8 + 2)^2 = (x + 1)^2 + 36 \]
\[ AC^2 = (x + 4)^2 + (-8 + 4)^2 = (x + 4)^2 + 16 \]
By Pythagorean theorem:
\[ AB^2 + BC^2 = AC^2 \]
\[ 13 + (x + 1)^2 + 36 = (x + 4)^2 + 16 \]
Simplify:
\[ 13 + x^2 + 2x + 1 + 36 = x^2 + 8x + 16 + 16 \]
\[ -6x = -18 \]
\[ x = 3 \]
In the figure below, \( L_1 \) and \( L_2 \) are parallel lines. The correct relationship between angles \( y \) and \( x \) is:

The angle supplementary to angle \( x \) on the right side of \( L_3 \) is equal to \( y \) since they are corresponding angles. Therefore:
\[ x + y = 180^\circ \]
If \( (x + y)^2 = 144 \) and \( x^2 - y^2 = 24 \), then what is \( x \) if \( x \) and \( y \) are both positive?
From first equation:
\[ x + y = 12 \quad \text{(taking positive root)} \]
Factor second equation:
\[ (x + y)(x - y) = 24 \]
Substitute \( x + y = 12 \):
\[ 12(x - y) = 24 \]
\[ x - y = 2 \]
Solve system:
\[ x + y = 12 \]
\[ x - y = 2 \]
Add equations:
\[ 2x = 14 \]
\[ x = 7 \]
How many 3-digit numbers can we make using the digits 4, 5, 7 and 9, where repetition is allowed?
For each of the 3 positions, we have 4 choices:
\[ 4 \times 4 \times 4 = 4^3 = 64 \]
A boat travels 10 miles East and then 24 miles South to an island. How many miles are there from the point of departure of the boat to the island?
Using Pythagorean theorem:
\[ d^2 = 10^2 + 24^2 = 676 \]
\[ d = \sqrt{676} = 26 \text{ miles} \]
What is the slope of any line perpendicular to the line \( -5x + 3y = 9 \)?
Find slope of given line:
\[ -5x + 3y = 9 \]
\[ 3y = 5x + 9 \]
\[ y = \frac{5}{3}x + 3 \]
Slope \( m_1 = \frac{5}{3} \)
Perpendicular slope \( m_2 \) satisfies:
\[ m_1 \cdot m_2 = -1 \]
\[ \frac{5}{3} \cdot m_2 = -1 \]
\[ m_2 = -\frac{3}{5} \]
Which of the following is a factor of the polynomial \( -2x^2 + 7x - 6 \)?
A) \( -2x - 3 \)
B) \( 2x + 2 \)
C) \( x - 6 \)
D) \( 2x - 2 \)
E) \( -2x + 3 \)
Factor the polynomial:
\[ -2x^2 + 7x - 6 = (-2x + 3)(x - 2) \]
Thus \( -2x + 3 \) is a factor.
\( \sqrt{(-9)(-4)} + \sqrt{(-4)} = ? \)
\[ \sqrt{(-9)(-4)} = \sqrt{36} = 6 \]
\[ \sqrt{(-4)} = \sqrt{-1 \cdot 4} = \sqrt{-1} \cdot \sqrt{4} = i \cdot 2 = 2i \]
\[ 6 + 2i, \quad \text{where } i = \sqrt{-1} \]
Find the linear function \( f \) such that \( f(2) = 5 \) and \( f(3) = -5 \).
Let \( f(x) = mx + b \)
From given conditions:
\[ f(2) = 2m + b = 5 \]
\[ f(3) = 3m + b = -5 \]
Subtract first equation from second:
\[ (3m + b) - (2m + b) = -5 - 5 \]
\[ m = -10 \]
Substitute to find \( b \):
\[ 2(-10) + b = 5 \]
\[ -20 + b = 5 \]
\[ b = 25 \]
\[ f(x) = -10x + 25 \]
A circular garden has an area of \( 100\pi \) square feet. What is the circumference of the garden in feet?
\[ \pi R^2 = 100\pi \]
\[ R^2 = 100 \]
\[ R = 10 \text{ feet} \]
Circumference:
\[ C = 2\pi R = 20\pi \text{ feet} \]
If \( \frac{5}{x} = 10 \) and \( \frac{2}{y} = 6 \), then \( \frac{x}{y} = ? \)
From first equation:
\[ \frac{5}{x} = 10 \Rightarrow x = \frac{5}{10} = \frac{1}{2} \]
From second equation:
\[ \frac{2}{y} = 6 \Rightarrow y = \frac{2}{6} = \frac{1}{3} \]
Therefore:
\[ \frac{x}{y} = \frac{1/2}{1/3} = \frac{3}{2} \]
If \( \frac{2^{m-3}}{4^{2m}} = 8 \), then \( 2m - 1 = ? \)
Rewrite in terms of base 2:
\[ 4^{2m} = (2^2)^{2m} = 2^{4m} \]
\[ 8 = 2^3 \]
Substitute:
\[ \frac{2^{m-3}}{2^{4m}} = 2^3 \]
\[ 2^{m-3-4m} = 2^3 \]
\[ 2^{-3m-3} = 2^3 \]
Equate exponents:
\[ -3m - 3 = 3 \]
\[ -3m = 6 \]
\[ m = -2 \]
\[ 2m - 1 = 2(-2) - 1 = -5 \]
In the figure below, \( ABC \) is a right triangle. Points \( B, C, D \) are collinear; points \( D, E, F \) are collinear and points \( B, A, F \) are collinear. The length of segments \( DC \) and \( DE \) are equal. What is the size, in degrees, of angle \( AFE \)?

In right triangle \( ABC \):
\[ \angle BCA = 90^\circ - 50^\circ = 40^\circ \]
Since \( DC = DE \), triangle \( DCE \) is isosceles:
\[ \angle DEC = \angle DCE = 40^\circ \]
Vertical angles: \( \angle AEF = \angle DEC = 40^\circ \)
Since \( \angle FAE = 90^\circ \):
\[ \angle AFE = 90^\circ - 40^\circ = 50^\circ \]
Which of the following is an equation of a line perpendicular to the line with equation \( 3x - 6y = 9 \)?
A) \( y = 2 \)
B) \( 3x + 6y = 9 \)
C) \( x - 2y = 3 \)
D) \( 2x + 2y = 3 \)
E) \( 2x + y = 7 \)
If \( a \) and \( b \) are any real numbers, then which of the following expressions is always positive?
A) \( |a| \)
B) \( |a + b| \)
C) \( |a - b| + \frac{1}{2} \)
D) \( a^2 + b^2 \)
E) \( (a + b)^2 \)
The geometric figure below consists of a right triangle and 2 semicircles. The diameters of the semicircles are the sides of the triangle. What is the area of the shaded region in square centimeters if the length of the hypotenuse of the triangle is 8 centimeters?

A) 64
B) \( 8\pi \)
C) \( 64\pi \)
D) \( 10\pi \)
E) 16
The mean of the numbers \( a, b, c, d, e \) is 23. The mean of the numbers \( a, b, c, d, e, f \) is 22. What is the value of \( f \)?
A) 23
B) 18
C) 22
D) 22.5
E) 20
Which of the following equations corresponds to the graph shown below?

A) \( y = (x - 3)^2 - 1 \)
B) \( y = -(x - 3)^2 + 1 \)
C) \( y = (x - 3)^2 + 1 \)
D) \( y = x - 3 \)
E) \( y = -(x - 3)^2 - 1 \)
Functions \( f \) and \( g \) are defined by \( f(x) = x^2 + x \) and \( g(x) = \sqrt{x + 6} \). What is the value of \( g(f(2)) \)?
A) 3
B) -3
C) 7
D) 6
E) -6
The sum of three consecutive integers is equal to 192. What is the product of these numbers?
A) 216000
B) 7077888
C) 576
D) 110592
E) 262080
What are the x-coordinates of the points intersection of the line with equation \( y = x + 1 \) and the circle with equation \( x^2 + y^2 = 5 \)?
A) -2, 0
B) 1, 2
C) -2, 1
D) -2, -1
E) 1, 3
\( \frac{1}{2}\sin(2x)(1 + \cot^2(x)) = \)
A) \( \tan(x) \)
B) \( \sin(x) \)
C) \( \cos(x) \)
D) \( \cot(x) \)
E) \( \sec(x) \)
Find the area of the rectangle ABCD shown in the figure below.

A) \( \frac{2500}{\sqrt{2}} \)
B) 2500
C) \( \frac{2500}{\sqrt{3}} \)
D) 1250
E) 5000
Solve for \( x \): \( \log_x(1024) = -5 \)
A) \( \frac{1}{4} \)
B) 4
C) \( \frac{1}{2} \)
D) \( \frac{1}{8} \)
E) 2
Simplify: \( 6\sqrt[3]{32} + 2\sqrt[3]{108} \)
A) 32
B) \( 18\sqrt[3]{2} \)
C) \( 36\sqrt[3]{2} \)
D) \( 18\sqrt[3]{4} \)
E) \( 36\sqrt[3]{4} \)
Evaluate: \( \frac{1}{(-5)^2} \)
A) \( -\frac{1}{25} \)
B) \( \frac{1}{25} \)
C) 25
D) -25
E) \( \frac{1}{10} \)