Question

Sal is cooking for a party. He opens a 11 lb bag of sugar. He uses 2/5 lb of the sugar for pies and another 3/8 lb of the sugar for cookies. How much sugar is left in the bag?

Answer 1

9/40 lb

Showing My Work:

2/5 and 3/8 don't have common denominators. So to change that, we have to multiply:

2/5 * 8/8 = 16/40

3/8 * 5/5 = 15/40

Then, we take both of these away from the bag's quantity (40/40)

40/40 - 15/40 - 16/40 = 9/40