Question

A person's present age is two-fifth of the age of his mother. After 8 years, he will be one-half of the age of his mother. How old is the mother at present?
A.32 years
B.36 years
C.40 years
D.48 years

Answer 1

let, present age of person is x and present age of his mother is y
then ATQ=> x=2/5y and (x+8)=1/2(y+8)
solving both eqn x=16 & y=40
hence correct opt is C

Answer 2

Answer:

C. 40 years

Step-by-step explanation:

Let Mother's present age be x

Person's present age = 2/5 × x

AFTER 8 YEARS

Mother's age = x+8

Person's age = 2x/5 + 8

But,

      Mother's age = 2 Person's age

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

      x+8                 = 4x/5 + 16

     x+8-16 = 4x/5

     x-8 = 4x/5

     5(x-8) = 4x

     5x-40 = 4x

     5x-4x = 40

     x = 40

MOTHER'S PRESENT AGE = 40 YEARS

PERSON'S PRESENT AGE = 2/5 × 40

                                           = 16 YEARS