A father was 12 times as old as his son 20 years back. Now he is twice as old as his son. What are their present ages?

Suppose the present age of son = P years
The present age of father = 2P years
According to question ,
20 years ago , (2P – 20) = 12 (P – 20)
⇒ 2P – 20 = 12P – 240
⇒ 12P – 2P = 240 – 20
⇒ 10P = 220
∴ P = 22 years
Age of father = 2P = 2 x 22 = 44 years