Question

At first, the ratio of Dave's savings to Sam's savings was 5:4. After each of them donated $40 to charity, the ratio of Dave's savings to Sam's savings became 13:10. What was Dave's savings at first?

Answer 1

Let the initial savings at first be = x

Given ratio is
`(5)/(4)` and after donating $40 to charity, the ratio becomes
`(13)/(10)`

Hence, the relation becomes:

`(5x-40)/(4x-40)=(13)/(10)`

`10(5x-40)=13(4x-40)`

=
`50x-400=52x-520`

`-2x=-120` or

`2x=120`

`x=60`

So , Dave's saving at first was 5x = 5*60 = $300

and Sam's saving at first was 4x = 4*60= $240