Question

15. Which one of the following statements expresses a true proportion?

A. 3 : 5 = 12 : 20
B. 14 : 6 = 28 : 18
C. 42 : 7 = 6 : 2
D. 2 : 3 = 3 : 2

Answer 1

Only ratio in A. is the same in both statements, as multiplying or dividing both of them by the same factor will not make a difference.

Answer 2

If we write the ratios vertically and then cross multiply:
A) 3*20 = 5 *15
60 = 60
B) 14 * 18 = 6 * 28
252 ≠ 168
C) 42 * 2 = 7 * 6
84 ≠ 42
D) 2 * 2 = 3 * 3
4 ≠ 9
Answer: A)