A 6-ounce box of strawberry gelatin costs $0.90 and a 3-ounce box costs $0.42. What is the difference in cost per ounce between the larger and the smaller boxes?
Cost per ounce for the 6-ounce box: $0.90 / 6 ounces = $0.15 per ounce
Cost per ounce for the 3-ounce box: $0.42 / 3 ounces = $0.14 per ounce
The difference in cost per ounce between the larger and smaller boxes is $0.15 - $0.14 = $0.01 per ounce.