Question

Today Mohan is 20 years younger than his father. Ten years ago he was one-half as old as his father. How old will his father be 10 years hence?

Answer 1

Answer: father's age 10 years hence = 60 years

Step-by-step explanation:

Let Mohan's age = M && Father's age = F

Present

M = F - 20 .... (i)

10 years ago:

Mohan's age = M -10  && Father's age = F - 10

(M-10) = 1/2 (F-10)

2*(M-10) = F - 10

2 M - 20 = F - 10

2 M - F = 10 .... (ii)

Substitute (i) in (ii)

2 [F - 20] - F = 10

2 F - 40 - F = 10

F = 10+40 = 50

Father's present age = 50

Father's age 10 years hence = 50 + 10 = 60 years