Joe spent $\$15.75$ on 21 pieces of fruit to make a salad.Bananas cost $\$.50$ each, oranges cost $\$.75$ each, and papayas cost $\$1.25$ each. Joe used twice as many oranges as bananas. How many of each fruit did he buy?
b = bananas
o = oranges = 2b
p = 21 - b - 2b
50 b + 75 (2b) + 1.25 ( 21- b - 2b) = 1575 solve for b = banans the oranges = 2b and papayas = 21-3b