b. 8 because Total Pieces Sold=60 
Pieces contributed by the cafeteria=20 
Pieces contributed by the clubs=x 
We can solve this problem by creating an equation to relate these terms: 
Total Pieces Sold= (pieces contributed by the cafeteria) + (pieces contributed by the clubs) 
Our equation is therefore: 60=20+x. We solve for x: 
60-20=x 
40=x 
This means the clubs contributed 40 pieces. To find out how many pies that equals, we can use the relationship: 
(40 pieces)/(y pies) = (5 pieces)/(1 pie). Solve for y: 
(1)(40)=(5)(x) 
(40/5)=8