Hitesh is three times as old as his son, and his daughter is 3 years younger than the son. If the sum of the ages of these three people 3 years ago was 123 years, then Hitesh's present age (in years) is:​

Correct option is A

Given:

Hitesh = 3 × son's age

Daughter = son's age – 3

3 years ago, total of their ages = 123 years

Solution: 

Let son's present age = x years

Then:

Hitesh's present age = 3x

Daughter's present age = x - 3

Ages 3 years ago:

Son = x - 3, Hitesh = 3x - 3, Daughter = x - 3 - 3 = x - 6

Now:

(x - 3) + (3x - 3) + (x - 6) = 123

5x - 12 = 123

5x = 135

x = 27

Hitesh's present age = 3x = 3 × 27 = 81 years