Susan buys black olives for $ 3 a pound and green olives for $ 5. a pound. $ 25 is spent. Buy 7 pounds total.
How many pounds of each type of olive did he buy?

Tomas used 3 1/3 cups of flour and now has 1 2/3cups left. which equation can he use to find f, the number of cups of flour he had to begin with? f+3 1/3=1 2/3 f-3 1/3=1 2/3 3 1/3f=1 2/3 f/3 1/3=1 2/3