Question

A man's age is 4 times his son's age. After 5 years, he will be 3 times as old as his son. Find their present ages.​

Answer 1

The present ages of son and father are 10 years and 40 years respectively.

Step-by-step explanation:

Given :

Man's age = 4 times the age of his son

After 5 years man will be = thrice the age of his son

To find :

Their present ages

Solution :

Let the present ages be -

Son as y

Father as 4y

\rule{300}{1.5}

Ages after 5 years -

Son = (y + 5)

Father = (4y + 5)

\rule{300}{1.5}

⇒ 4y + 5 = 3(y + 5)

⇒ 4y + 5 = 3y + 15

⇒ 4y - 3y = 15 - 5

⇒ y = 10

Son's present age = 10 years

\rule{300}{1.5}

★ Value of 4y

⇒ 4(10)

⇒ 40

Father's present age = 40 years

∴ The present ages of son and father are 10 years and 40 years respectively.