Practice Test 18 - ACT Math

20 questions. Answer them in any order, then submit to see your score and every explanation.

  1. What is the area of a circle with diameter 14?
  2. In the diagram, two lines intersect, forming angles AA, BB, CC, and DD. Angle AA measures 100∘100^\circ. What is the measure of angle CC, which is a vertical angle to AA?
  3. Which value of xx satisfies the equation 3x+4=x+183x + 4 = x + 18?
  4. A complex number is given by −9−12i-9 - 12i. To find its distance from the origin, compute its absolute value. What is the absolute value of (−9−12i)(-9 - 12i)? (Simplify the radical.)
  5. In the right triangle shown, the right angle is at BB. The side lengths are AB=3AB=3, BC=4BC=4, and AC=5AC=5. Angle θ\theta is at AA (between ABAB and ACAC). What is sin⁡(θ)\sin(\theta)?
  6. If  6(x+2)−3=21 \,6(x + 2) - 3 = 21\,, what is xx?
  7. A ball is thrown upward from a height of 5 meters. Its height after xx seconds is modeled by the quadratic equation y=−4x2+12x+5y = -4x^2 + 12x + 5, where yy is height in meters. According to the model, what is the height of the ball after 22 seconds?
  8. How many permutations of 5 letters taken 3 at a time?
  9. A shipment is packed into identical boxes. If the total number of items is given by 6x=546x = 54, what is the value of xx?
  10. Which formula gives the surface area of a right circular cylinder with radius rr and height hh (including both circular bases)?
  11. To remove imaginary terms from a denominator later, you plan to multiply by a conjugate. What is the complex conjugate of 8−11i8 - 11i?
  12. Two triangles are shown with side lengths. Triangle △GHI\triangle GHI has GH=7GH=7, HI=9HI=9, and GI=12GI=12. Triangle △JKL\triangle JKL has JK=14JK=14, KL=18KL=18, and JL=20JL=20. Are the triangles similar? If so, why?
  13. What is the median of the data set [9, 5, 12, 8, 7]?
  14. A coffee shop sells muffins for $3 each. Jordan buys 4 muffins and pays with a $20 bill. How much change does Jordan receive?
  15. Simplify: 5a2−3a+2a2+7a5a^2-3a+2a^2+7a.
  16. The times (in minutes) it took a runner to complete a short course over 8 trials were: 9, 12, 11, 10, 13, 10, 14, 8. What is the median of {9,12,11,10,13,10,14,8}\{9, 12, 11, 10, 13, 10, 14, 8\}?
  17. In the standard (x,y)(x, y) coordinate plane, what is the slope of the line given by the equation 5x+2y=105x + 2y = 10?
  18. In a circle of radius 44, arc EF⌢\overset{\frown}{EF} is subtended by a central angle of 135∘135^\circ. What is the length of arc EF⌢\overset{\frown}{EF}?
  19. What is tan⁡(π4)\tan(\frac{\pi}{4})?
  20. What is the measure of each interior angle in a regular decagon (10-gon)?

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