At present, A is younger than B by 8 years. If 4 years ago, their ages were in the ratio 1 : 2, then what is the present age of B (in years) ?

20

ATQ,

Lets assume, present age of A is x and B is x + 8

Given, 4 years ago ratio of their ages ⇒ \(\frac{x - 4}{x + 8 - 4}\) = \(\frac{1}{2}\)

                                                       ⇒ x = 12

Present age of B = 20 years