On a scale drawing of caleb’s house, the four bedroom walls each measure 10 inches wide by 6 inches tall. the scale of the drawing is 1 inch = 1.5 feet. caleb will paint all four walls. if a gallon of paint covers 250 square feet, how many gallons of paint will caleb need?
C) 3 gallons
Explanation:
1 inch = 1.5 feet
10 inches = 15 feet (multiply both sides by 10)
6 inches = 9 feet (multiply both sides of the first equation by 6)
The scale drawing is 10 inches by 6 inches, which corresponds to real life dimensions of 15 ft by 9 ft.
The area of the one wall is 15*9 = 135 square feet.
There are four identical walls of equal area, so 135*4 = 540 square feet is the total area we need to paint.
1 gallon = 250 square feet
0.004 gallon = 1 sq ft (divide both sides by 250)
2.16 gallon = 540 sq ft (multiply both sides by 540)
You'll need exactly 2.16 gallons of paint to cover all four walls.
Since Caleb cannot buy 0.16 of a gallon, he'll need to buy an additional gallon to cover the fractional portion. So he'll need to buy 3 gallons of paint and he'll have 3-2.16 = 0.84 gallons of paint left over.