Find the money that both the girls will equally have.
76/2 = 38
So, imagine this, take 7 dollars from girl 2 and give it back to girl 1, you would essentially to the opposite of what the question said.
So, girl 2: 38 - 7 = 31
Girl 1: 38 + 7 = 45
To test if we got it right, add 31 and 46, and we get 76!
