A was twice as old as B, two years ago. If the difference in their ages be 2 years, find A's age.

Suppose the present age of B = P years
The present age of A - The present age of B = 2 years.
Therefore, the present age of A = P + 2 years
According to question,
Two years ago , 2( the present age of B - 2 years ) = the present age of A - 2 years
2 (P – 2) = P + 2 – 2
⇒ 2P – 4 = P
⇒ 2P – P = 4
∴ P = 4
Age of B = 4 years
Age of A = P + 2 = 4 + 2 = 6 years