SOLUTION: Al can wash the family car in 60 minutes while it takes his little brother Bill 80 minutes to wash the car. How long will it take them to wash the car working together? I know..

Question 874787: Al can wash the family car in 60 minutes while it takes his little brother Bill 80 minutes to wash the car. How long will it take them to wash the car working together?
I know...
t = time
1/60 + 1/80 = 1/t

Answer by ewatrrr(24785) (Show Source): You can put this solution on YOUR website!

 

Hi

Good Work on Set Up

1/60 + 1/80 = 1/t  |Multiplying thru by 240 so as all denominators = 1

  4x + 3x = 240

   7x = 240

      x = 240/7 = 34.3 min (nearest tenth) 

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