Professor

Five years ago, the age of father was 7 times of his son. After five years, the age of the father will be 3 times of the age of the son. Find out the present age of the father and son.

- 36 years and 12 years
- 49 years and 7 years
- 20 years and 8 years
- 40 years and 10 years

Asked by Anurag Mishra on 6th September 2015 in Maths.

1 Answers

Professor

**Answer: (4) 40 years and 10 years
Explanation:-**

Let the age of father be X years and the age of his son is Y years.

Five years ago,

(X – 5) = 7(Y – 5)

X – 5 = 7Y – 35

X – 7Y = -35 + 5

X – 7Y = -30 ……………… (1)

According to second condition,

After five years,

(X + 5) = 3(Y + 5)

X + 5 = 3Y + 15

X – 3Y = 15 – 5

X – 3Y = 10 ………………….. (2)

Equation (1) is subtract from equation (2),

Then,

X – 3Y –X + 7Y = 10 + 30

4Y = 40

Y = 40/4

Y = 10 years

Put the value of Y = 10 in equation (2),

X – 3 x 10 = 10

X = 10 + 30

X = 40 years.

Then, the present age of father is Y = 40 years and the present age of his son is X = 10 years

Hence, the answer is (4) 40 years and 10 years.

Answered by Anurag Mishra on 7th September 2015..