Question

Mrs.wilkinson can buy a 20 -ounce box of cereal for $3.60 or a 28-ounce box of cereal for $4.20 .Which is better buy ?Explain your answer

Answer 1

We need to work out the unit price, that is, the cost of 1 ounce of each.

If 20oz cost $3.60, then 1oz costs 3.60/20=1.80/10=18c.

If 28oz cost $4.20, then 1oz costs 4.20/28=0.60/4=15c.

So the 28oz box is cheaper and the better buy.