At present, the difference of the ages of a mother and son is 30 years. 15 years ago, the mother’s age was twice the then age of the son. The present age (in years) of the mother is:

Question

Question

This question was previously asked in

RRB Group D 6 Oct 2022 Shift 1 Official Paper

Answer 1

Given:

At present, the difference of the ages of a mother and son is 30 years.

15 years ago, the mother’s age was twice the then. age of the son.

Calculation:

Let the present age of the mother be x and the son be y.

⇒ x – y = 30

⇒ x = 30 + y → (1)

Now, 15 years ago

Mother's age = x – 15

Son's age = y – 15

⇒ x – 15 = 2(y – 15)

⇒ x – 2y = –30 + 15 = –15

⇒ x = 2y – 15 → (2)

Equating both equations (1) and (2), we get

⇒ 30 + y = 2y – 15

⇒ y = 30 + 15 = 45

Present age of mother = x = 30 + 45 = 75

Therefore, the present age of mother is 75 years.