SOLUTION: it takes John three times as long to clean an office building as Lisa. If they work together, it takes 6 hours to clean. How long does it take Lisa by herself?

Algebra ->  Rate-of-work-word-problems -> SOLUTION: it takes John three times as long to clean an office building as Lisa. If they work together, it takes 6 hours to clean. How long does it take Lisa by herself?       Log On


   

Question 845064: it takes John three times as long to clean an office building as Lisa. If they work together, it takes 6 hours to clean. How long does it take Lisa by herself?


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

Hi,

John three times as long to clean an office building as Lisa's time+highlight_green%28x%29

+1%2F%283x%29+%2B+1%2Fx+=+1%2F6+     |Multiplying thru by 6x so as all denominators = 1

   2 + 6 = x

    8 = x, time it takes Lisa alone.