SAT Math Question of the Day

Math Category: Fractions Level 2:

Q: If 3/2 = 21/a, then a is equal to:

  1. 8
  2. 10
  3. 12
  4. 14
  5. 16

UNANSWERED.

The correct answer is D.

A: The answer is 14.

To solve this problem, cross-multiply.
3/2 = 21/a
3 × a = 2 × 21
3a = 42
a = 14