Question

A boy is 10 years older than his brother. In 4 years he will be twice as old as his brother. Find their present age

Answer 1

The older boy's present age is 16.

The younger boy's present age is 6.

In four years, the older boy will be 20 and the younger boy will be 10 which would make the older boy twice as old as the younger boy.

Answer 2

Brother: x

Boy: x + 10

Ages in 4 years:

Brother:  x + 4

Boy: x + 10 + 4  or  x + 14

In the Equation form it will look like this:

x + 14 = 2 (x + 4)

x + 14 = 2x + 8

14 - 8 = 2x - x

x = 6

Present Ages:  

A boy is 10 years older than his brother.

    Brother: x = 6 years old

    Boy: 6 + 10 = 16 years old

Ages in 4 years:  

The boy will be twice as old as his brother.

    Brother: 6 + 4 = 10 years old

    Boy: 16 + 4 = 20 years old