math
posted by RACHEL .
David and Peter had $90 and $200 respectively. They were each given an equal amount of money. Then Peter had twice as much money as David. How much money did each boy receive?

I think it should be calculated like this:
Let x be the amount of money each boy received
2*(90+x)=200+x or 90+x=(200+x)/2
180+2x=200+x
x=20
Therefore, each boy received $20