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Inequalities (linear and compound) — ACT practice questions

Inequalities (linear and compound) on the ACT Mathematics test covers linear inequalities, compound statements with and or or, and absolute-value ranges on the real line. A student must isolate the variable, reverse the inequality when multiplying or dividing by a negative, and tell inclusive bounds from exclusive ones. Questions typically ask which inequality matches a verbal condition, which set is the solution, or which step in a growing pattern first exceeds a stated limit. The five answer choices usually look alike, swapping at most with at least, mixing open and closed endpoints, or reversing the inequality sign.

  • Section: Mathematics 45 questions on the paper
  • 46 practice questions in the app

Sample questions

Question 1

Which of the following is the solution of 5<3x+113-5<3x+1\leq13?

  1. A2<x4-2<x\leq4
  2. B2x<4-2\leq x<4
  3. C1<x5-1<x\leq5
  4. D6<x12-6<x\leq12
Show answer

Answer: A — 2<x4-2<x\leq4

Subtracting 1 gives 6<3x12-6<3x\leq12. Dividing all three parts by 3 gives 2<x4-2<x\leq4.

Question 2

Which of the following inequalities represents all real numbers mm whose distance from 50 is at most 3?

  1. Am503|m-50|\le3
  2. Bm350|m-3|\le50
  3. Cm503|m-50|\ge3
  4. Dm+50<3|m+50|<3
Show answer

Answer: A — m503|m-50|\le3

The expression m50|m-50| is the distance from mm to 50. Requiring that distance to be at most 3 gives m503|m-50|\le3.

Question 3

A collector's display case holds 12 coins in its first row. Each row after that holds 7 more coins than the row before it. Which row is the first to contain more than 100 coins?

  1. A12
  2. B13
  3. C14
  4. D15
Show answer

Answer: C — 14

Row nn holds 12+7(n1)12+7(n-1) coins. Row 13 holds 12+7(12)=9612+7(12)=96 coins, and row 14 holds 12+7(13)=10312+7(13)=103 coins, the first total exceeding 100.

Practice 46 Inequalities (linear and compound) questions in the app

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