Father is 30 years older than son. After 10 years he will be twice the son's age. Son's current age:

1. Let son's age = x. Then father = x + 30. 2. After 10 years: father = x+40, son = x+10. Given (x+40) = 2(x+10). 3. x = 20. Hence 20 years. _Source: UGC NET Paper 1 Study Book (ugc-net.com class notes) — Ages_