Answer:
i. Mallory should buy the 10-ounce box of cereal.
ii. Difference is that the 13-ounce cost more on 1-ounce.
Step-by-step explanation:
First find the ounce/cost. Which 1-ounce of the $2.79 box of cereal is $0.28/ounce. The $3.99 box of cereal is $0.31/ounce. Therefore the $2.79 is cheaper to buy. The difference is 13-ounce box (which is 3 cents more) cost more in ounce than the 10-ounce.