Mary has 40$, John has 160$, and Fred has 80$. What I did was see how many Mary's money it would take to get 280. John = 4x, and Fred then = 2x. 4x + 2x + x = 7x. Divide 280 by 7 to get 40, which is Mary's savings. Then for John, do 40 times 4, and then 40 times 2 to get Fred's.