Question

A, B, C are positive integers such that A:B = 7:9 and B:C = 12:7, what is the smallest possible value of A?

Answer 1

28

Explanation:

A/B = 7x/9x

B/C = 12y/7y

9x=12y

x=12/9=4/3y

7x = 7*(4/3)*y = 7*(4/3) = 28/3 - not an integer

7*(4/3)*2 = 56/3 - not an integer

7*(4/3)*3 = 28