Question

The age of prakash is 4times the age of his son. After 10 years the age of prakash will be only twice the age of his son. Find the present age of prakash's son ?

Answer 1

here
let age of Prakash be x yrs
let age of his son be y yrs
so according to the question ,
x=4y
x+10=2(y+10)
so from here,
x=20yrs
and y=5yrs

Answer 2

let the age of Prakash son be x and Prakash age be " y ".
according to the question,
then Prakash age will be " 4y " and his sons age will be " x ".

4y = x
after 10 yrs
prakash age :4x+10
Prakash son age :x+ 10
according to the question
4x+10 = (x+ 10)2
4x+10 = 2x+20
2x =10
x = 5

Prakash son's age : 5 yrs
and his age will be 20 yrs