Answer:
Mrs. Smith need to buy every week 7 cartons and the remaining 1.4 gallon of apple juice can be used the next week
Explanation:
Total apple juice the Smith family drinks per week = 1 4/5 * 7
Total apple juice the Smith family drinks per week = 1.8 * 7
Total apple juice the Smith family drinks per week = 12.6 gallons
If a carton contains 2 gallons, the number of cartons Mrs. Smith need to buy every week is:
Total apple juice the Smith family drinks per week/2
12.6/2 = 7 cartons and 1.4 gallon can be used for the next week