2 Answers

Shyam S · Answer 1 · 2018-07-18T13:42:00+0000

I really want to say A, I mean all of these would fit for the one third of their ages but the two-fifths is kinda tricky. But I am sticking with A.

Anurag Soni · Answer 2 · 2018-07-22T07:48:53+0000

Answer:

Option: A is the correct answer.

A girl is 9; mom is 27

A girl is now one-third as old as her mother.

i.e. if x is the present age of girl.

and y is the present age of her mother.

Then,

x=(1)/(3)y

i.e.

y=3x-----------(1)

In three years, she will be two-fifths as old as her mother will be.

This means after three years.

The age of girl will be: x+3

and the age of her mother will be: y+3

This means that:

(x+3)=(2)/(5)* (y+3)

$5(x+3)=2(y+3)\\\\i.e.\\\\5x+15=2y+6$

i.e.

5x+15=2* 3x+6

( since on using equation (1) )

i.e.

$5x+15=6x+6\\\\i.e.\\\\6x-5x=15-6\\\\i.e.\\\\x=9$

and the value of y from equation (1) is:

y=27