Amy, ruben, and sam have a total of $71 in their wallet. sam has 3 times what reuben has. reuben has $9 more than amy. how much do they have in their wallets?

Total = amount Amy has(A) + amount Ruben has(R) + amount Sam has(S)
S = 3 * R
R = A + 9

S = 3 * (A+9)
S = 3A + 27

71 = A + (A + 9) + (3A + 27)
71 = 5A + 36
5A = 35
A = $7

R = A + 9
R = 7 + 9
R = $16

S = 3 * R
S = 3 * 16
S = $48