Question

Calculate the Mother's Age
A person's present age is two fifth of the age of his mother after 8 years he willl be one-half of the age of his mother. How old his mother at present?

Answer 1

Let us assume, Mother's age is x years and person's age is y years.
Given:
y = 2/5 * x -----------1
After 8 years,

y + 8 = 1/2 (x + 8) 
2 (y  + 8) = x + 8
2y + 16 = x + 8
x - 2y = 8 -----------2
Substitute the value of y from equation 1 in equation 2
x - (2 * 2/5 x) = 8
5x - 4x = 40
x =40
Therefore, y = 2/5 * x = 2/5 * 40 = 16
Therefore, mother's present age is 40 years.

Answer 2

Answer:

Let the mother age be x years.

Then, the persons present age will be 2/5 x years.

According to Question now,

(2/5 x + 8) = 1/2 x + 8

2(2x + 40) = 5(x + 8)

x = 40 years.