SOLUTION: Mike, Louie and Joy can mow the lawn in 4,6, and 7 hours, respectively. What fraction of the yard can they mow in one hour if they work together?

Algebra ->  Rate-of-work-word-problems -> SOLUTION: Mike, Louie and Joy can mow the lawn in 4,6, and 7 hours, respectively. What fraction of the yard can they mow in one hour if they work together?      Log On


   

Question 89768: Mike, Louie and Joy can mow the lawn in 4,6, and 7 hours, respectively. What fraction of the yard can they mow in one hour if they work together?
Answer by Edwin McCravy(20060) About Me  (Show Source):
You can put this solution on YOUR website!

Mike, Louie and Joy can mow the lawn in 
4,6, and 7 hours, respectively. What fraction of
the yard can they mow in one hour if they work 
together?

Since Mike can mow the lawn in four hours, then in one
hour he can mow one-fourth of the lawn.  It's similar
reasoning for the others, so: 

In one hour, Mike can mow 1%2F4th of the lawn
In one hour, Louie can mow 1%2F6th of the lawn
In one hour, Joy can mow 1%2F7th of the lawn

So in one hour they can mow 1%2F4%2B1%2F6%2B1%2F7 = 21%2F84%2B14%2F84%2B12%2F84 =
47%2F84ths of the lawn. That's about 56% of the lawn. 

Edwin