Option 5 : 35 years

**Given:**

Ratio of ages of A and B after 5 years = 5 : 8

Sum of their ages after 8 years = 71 years

**Calculation:**

Let the ages of A and B after 5 years be 5x and 8x respectively

Age of A after 8 years = 5x + 3

Age of B after 8 years = 8x + 3

Now, according to question

⇒ 5x + 3 + 8x + 3 = 71

⇒ 13x + 6 = 71

⇒ 13x = 65

⇒ x = 5

Age of B after 5 years = (8 × 5) years

⇒ 40 years

present age of B = (40 – 5) years

⇒ 35 years

**∴ Present age of B is 35 years**