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