SOLUTION: The JUST-SAY-MOW lawn mowing company consists of two people: Marsha and Bob. If Marsha cuts the lawn by herself, she can do it in 3 hours. If Bob cuts the same lawn himself, it tak
Algebra ->
Rate-of-work-word-problems
-> SOLUTION: The JUST-SAY-MOW lawn mowing company consists of two people: Marsha and Bob. If Marsha cuts the lawn by herself, she can do it in 3 hours. If Bob cuts the same lawn himself, it tak
Log On
Question 1120578: The JUST-SAY-MOW lawn mowing company consists of two people: Marsha and Bob. If Marsha cuts the lawn by herself, she can do it in 3 hours. If Bob cuts the same lawn himself, it takes him an hour longer than Marsha. How long would it take them if they worked together? Round to the nearest hundredth of an hour. Answer by ikleyn(52778) (Show Source):
Marsha can do the job in 3 hours. She makes of the job per hour. It is her rate of work.
Bob can do the job in 4 hours. He makes of the job per hour. It is his rate of work.
Working together, they make + = + = of the job per hour.
(Their combined rate of work is the sum of individual rates.)
Hence, the time needed to complete the job for the two working together is hours = hours
= 1.714 hours = 1 hour and 43 minutes (approximately).
