The ratio of the present ages of A and B is 7 : 8.  After 8 years, this will become 9 : 10 .  C is 3 years younger to B.  What is the present age of C?

29 years

Lets Present age of A & B = 7x   &   8x

ATQ,

⇒ \(\frac{7x + 8}{8x + 8}\) = \(\frac{9}{10}\)

⇒ 70x + 80 = 72x + 72

⇒ 8 = 2x 

⇒ x = 4

So, age of B = 8x = 8 × 4 = 32 years

Age of C = 32 - 3 = 29 years