College Readiness Math Flashcards

Which of the following is equivalent to 2^(−3)?

Answer: 1/8

A negative exponent means the reciprocal: 2^(−3) = 1/2³ = 1/8.

If 40% of a number is 28, what is the number?

Answer: 70

0.40 × n = 28, so n = 28 / 0.40 = 70.

What is the range of f(x) = −x² + 4?

Answer: y ≤ 4

The parabola opens downward with vertex at (0, 4), so y can be at most 4.

Which equation represents a line parallel to y = 2x − 1?

Answer: y = 2x + 5

Parallel lines have the same slope; y = 2x + 5 has slope 2, matching the original.

A boat travels upstream at 8 mph and downstream at 12 mph. What is the speed of the current?

Answer: 2 mph

Current = (downstream − upstream) / 2 = (12 − 8) / 2 = 2 mph.

Solve: 2/(x+1) = 4/(x+3)

Answer: x = 1

Cross-multiply: 2(x+3) = 4(x+1) → 2x+6 = 4x+4 → 2 = 2x → x = 1.

A data set has values 5, 8, 8, 10, 14. Which measure of central tendency equals 8?

Answer: Median and mode

Median (middle value) = 8 and mode (most frequent) = 8; mean = 45/5 = 9.