Question

Bobby put 1/3 of his lawn mowing money into his savings and uses the remaining 2/5 to buy a video game. If he has $12 left, how much did he have at first?

Answer 1

Given:

Bobby put 1/3 of his lawn mowing money into his savings

He uses the remaining 2/5 to buy a video game.

He has $12 left.

To find:

The amount did he have at first.

Solution:

Let x be the initial amount.

Bobby put 1/3 of his lawn mowing money into his savings. So, the remaining amount is

`x-(1)/(3)x=(2)/(3)x`

He uses the remaining 2/5 to buy a video game. Then the remaining amount is

`Remaining=(2)/(3)x-(2)/(3)x* (2)/(5)`

`Remaining=(2)/(3)x-(4)/(15)x`

`Remaining=(10x-4x)/(15)`

`Remaining=(6x)/(15)`

`Remaining=(2x)/(5)`

It is given that the remaining amount is $12.

`12=(2x)/(5)`

`12* 5=2x`

`60=2x`

Divide both sides by 2.

`(60)/(2)=x`

`30=x`

Therefore, Bobby have $30 at first.