Question

Huong covered a box with sticky-backed decorating paper. The paper costs $.03 per square inch. How much money will Huong need to spend on paper if the length is 7 inches, width is 3 inches, and the height is 9 inches?

I thought Huong needed to spend $3.42 because I multiplied 0.3x9 and got .27, 0.3x3 and got .09, and 0.3x7 and got .21. Then I added .27, .09, and .21 and got .57 then I multiplied .57x6 (due to the number of sides) and got 3.42. If I am incorrect please help me on how to solve this problem, if I am correct please let me know. Thank you.

Answer 1

there are three pairs of matching sides

two are L x W ___ 2 * 7 * 3

two are L x H ___ 2 * 7 * 9

two are W x H ___ 2 * 3 * 9

find the areas, add them together
multiply by the paper cost

Answer 2

76