Question

CJ was painting his apartment. In 15 minutes, 1 CJ had used gallon of paint. Write an equation that represents the gallons of paint used, y, in x hours.

Answer 1

Take into account that the relation in between gallons used and time is given by:

y = kx

where k is the constant of proportionality.

Consider that CJ used 1 gallon of paint in 15 minutes. Then, the constant of proportionality is:

k = 1 gallon/15 min

however, due to x is in hours, it is necessary to rewrite k as follow:

k = 1 gallon/0.25 hour = 4 gallons/hour

Then, the equation is:

y = 4x