Question

Which pair of ratios can form a true proportion?
A 9/12 , 5/8
B 25/20 , 16/21
C 6/27 , 2/9
D 7/12 , 10/15

Answer 1

proportions are nothing but equivalent fractions
so reduce all the fractions and see which ones are equal

9/12 = 3/4
5/8 does not reduce....this is not a proportion

25/20 = 5/4
16/21 does not reduce....this is not a proportion

6/27 = 2/9
2/9 = 2/9 <==== BINGO...these are proportional

7/12 -- this does not reduce
10/15 = 3/5......this is not a proportion