It takes 90 minutes to wash 20 vehicles at a car wash. At this rate, how many minutes does it take to wash 5 vehicles?

1 Answer
Apr 24, 2016

22.5 minutes

Explanation:

Make a proportion:
text{minutes}/text{number of vehicles}

text{90 minutes}/text{20 vehicles } = x/text{5 vehicles}

Cross multiply and solve for x
90(5) = 20(x)
450 = 20x
22.5 = x

Answer: 22.5 minutes