Given: Ratio of ages of father and son, 7 years ago = 4 : 1 Ratio of ages of father and son, 7 years hence = 2 : 1 Calculation: Let the age of father and son 7 years ago be 4x and x respectively Age of father 7 years hence =4x+7+7 ⇒4x+14 Age of son 7 years hence =x+7+7 ⇒x+14 Now, according to question, (4x+14)/(x+14)=2/1 ⇒4x+14=2x+28 ⇒2x=14 ⇒x=7 Present age of father =4x+7 ⇒4×7+7 years ⇒ 35 years Age of son =x+7 ⇒7+7 years ⇒ 14 years Required ratio = 35 years : 14 years ⇒5:2 ∴ The ratio of their present ages is 5 : 2