The difference between the ages of the two men is 10 years. 15 years ago, the elder one was twice as old as the younger one. The present age of the elder man is-

Question: The difference between the ages of the two men is 10 years. 15 years ago, the elder one was twice as old as the younger one. The present age of the elder man is-

Solution:
Let, their ages be x years and (x + 10) years.

ATQ,
(x + 10 - 15) = 2(x - 15)
⇒ x - 5 = 2x - 30
⇒ 2x - 30 - x + 5 = 0
⇒ x - 25 = 0
∴ x = 25

∴ Present age of the elder man = x + 10 = 25 + 10 = 35 years.