Question

Penny used 2/5lb. Of flour to bake a vanilla cake. She used another 3/4lb. Of flour to bake a chocolate cake a. How much flour did she use for both cakes? B. If she started with a 5lb. Bag, How much flour does she have left?

Answer 1

A. How much flour did she use for both cakes?

1 3/20 lb flour

B. If she started with a 5lb. Bag, How much flour does she have left?

3 17/20 lb

Explanation:

Penny used 2/5lb. Of flour to bake a vanilla cake. She used another 3/4lb. Of flour to bake a chocolate cake

A. How much flour did she use for both cakes?

We solve the above question by adding up the pound of flour used for both cakes.

2/5lb Of flour + 3/4lb Of flour

Lowest common denominator = 20

= 8 + 15/20

= 23/20

= 1 3/20 lb flour

B. If she started with a 5lb. Bag, How much flour does she have left?

This is calculated as:

5 lb - 1 3/20 lb

= 3 17/20 lb