Answer:
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