Correct Answer - Option 1 : 48

**Given:**

The ratio of ages of Monu and Sonu at present is 4 ∶ 1.

Eight years ago Monu's age was 10 times the age of Sonu.

**Calculation:**

Let the present age of Monu and Sonu be 4x and x.

The age of Monu eight years ago = 4x - 8

The age of Sonu eight years ago = x - 8

According to the question;

⇒ 10( x - 8) = 4x - 8

⇒ 10x - 80 = 4x - 8

⇒ 6x = 72

⇒ x = 12

The present age of Monu = 4 × 12 = 48 years

**∴ The present age of Monu is 48 years.**