Answer:
12 minutes
Step-by-step explanation:
First we figure out how much of a car each person can wash in 1 minute.
Shea can wash the car by herself in 20 minutes
Therefore, she can wash a car in 1 minute = [tex]\frac{1}{20}[/tex]
Tucker can wash a car in 30 minutes.
Tucker can wash the car in 1 minute = [tex]\frac{1}{30}[/tex]
Thus, in one minute together they wash a car
[tex]\frac{1}{20}[/tex] + [tex]\frac{1}{30}[/tex] = [tex]\frac{50}{600}[/tex] = [tex]\frac{1}{12}[/tex]
In one minute together they can wash = [tex]\frac{1}{12}[/tex] of a car
Time needed to wash entire car together = 12 minutes.
It takes them 12 minutes to wash the car.
