The ratio of the present ages of A and B is 8 : 9.  After 9 years, this will become 19 : 21.  C is 3 years younger to B.  What is the present age of C?

54 58 51 52

51

Present age of A & B = 8x   :    9x ATQ, ⇒ \(\frac{8x + 9}{9x + 9}\) = \(\frac{19}{21}\) ⇒ 168x + 189 = 171x + 171 ⇒ 18 = 3x  ⇒ x = 6 So, age of B = 9x = 9 × 6 = 54 years Age of C = 54 - 3 = 51 years