Question

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

A.
because 3:5
12:20 <--- is multiplied 4 times

3 times 4 is 12, 5 times 4 is 20. so it has true proportion

Answer 2

For the pair of ratios to be proportional, the quotients obtained from dividing the first number by the second should be the same for both. This condition is satisfied only by the first choice wherein the first ratio equals 3/5 and the second ratio is also 3/5. Thus, the answer is letter A.