Geometry/ Algebra

Question

all four walls of a rectangular room is 14 ft wide, 20 ft long, and 8 ft high, are to be painted. what is the minimum cost of paint if one gallon covers at most 130 sq ft and the paint costs $22 per gallon?

1.) $92

2.) $102

3.) $110

4.) $190

Answer 1

Need to start with the total square footage to be painted:

(2) short walls @ 14' x 8' = 112 x 2 = 224 sq ft.

(2) long walls @ 20' x 8' = 160 x 2 = 320 sq ft.

So total area to be painted is 544 sq ft.

i gal covers 130 sq ft,, so you will need 544/130 = 4.18 gals of paint.

Unfortunately you have to buy in 1 gallon increments, so you will need to buy 5 gals!

5 gal x $22/gal = $110