How much paint would be needed?

Question

If 3/4 gallon of paint covers 250 square feet of wall space, how much paint would be needed for a room with 510 square feet of wall space? 

Answer 1

To solve this problem we set up a proportion, which sets two ratios equal to each other:

0.75 gallons of paint x gallons of paint

--------------------------- = -----------------------

250 square feet 510 square feet

(3/4 = 0.75 in decimal)

We want to find x, the gallons of paint for 510 square feet of wall. To do this we cross-multiply:

250 square feet * x gallons of paint = 510 square feet * 0.75 gallons of pain

dividing both sides by 250 square feet:

x gallons of pain = 510 square feet * 0.75 gallons of paint x = 1.53 --> need 1.553 gallons of paint

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250 square feet