A contractor finds that 4 gallons of paint will cover 900 sq

A contractor finds that 4 gallons of paint will cover 900 sq ft of wall area. How much wall area could be covered with 12 gallons of paint?

Solution

4 gallons of paint covers 900 sq ft

let 12 gallons of paint covers x sq ft

so writing the ratio of gallons to paint

4 / 900 = 12 / x

cross multiplying

4x = 900 * 12

x = 900 * 12 / 4 = 2700 sq feet