SOLUTION: Please help. Jack mows a lawn in 4 hours. Mary mows the same lawn in 3 hours. How much time would it take for both of them to mow the yard? Thank you.

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: Please help. Jack mows a lawn in 4 hours. Mary mows the same lawn in 3 hours. How much time would it take for both of them to mow the yard? Thank you.      Log On


   

Question 177379: Please help. Jack mows a lawn in 4 hours. Mary mows the same lawn in 3 hours. How much time would it take for both of them to mow the yard? Thank you.
Answer by Mathtut(3670) About Me  (Show Source):
You can put this solution on YOUR website!
so Jack mows 1/4 of the lawn per hour and Mary mows 1/3 of the lawn per hour
:
together they mow
((1/4)+(1/3) of the lawn per hour
:
(3/12)+(4/12)=7/12 of the lawn per hour
:
(7/12)t=1(job)
:
highlight%28t=12%2F7%29hours