Question

Five years ago, A was thrice as ols as B. Ten years later, A will be twice as old as B. How old are they now?

Answer 1

Let us assume, the present age of A is x years and present age of B is y years.

Given that five years ago,

x – 5 = 3 (y – 5)

x – 5 = 3y – 15

3y – x = 10 ------------1

Ten years later,

x + 10 = 2 (y + 10)

x + 10 = 2y + 20

x – 2y = 10 ----------2

Add equation 1 and 2

y = 20 years

Therefore,

x = 3y – 10 = 3*20 -10 = 50 years

A is 50 years and B is 20 years old.