Question

Helen spent 3/8 of her money at the first store she visited. She then spent 3/4 of her remaining money at the second store. If Helen had $20 left, how much money did she start with?

Answer 1

`$128`

Explanation:

After spending `3/8` of the money, Helen had `5/8` left.

Then she spent `3/4` of the remaining `5/8`.

That would mean by the time she is done, she'd have `1/4` of `5/8` left

`1/4 times 5/8 = 5/32`

we know that the money she had left was `$20`

Therefore `$20 = 5/32`

The amount of money Helen started with would be equal to
`32/32` `= 1/1` because that is 100%, it's all of her money

There are multiple ways to reach `32/32` with algebra. Here's one way:

Multiply both sides of ' `$20 = 5/32`' by 32

That gives `$640 = 5`

Now divide both sides by 5

This gives `$128 = 1`

The `1` represents the fraction of money she has, meaning that 1 is the total amount.