Results 1 to 4 of 4
Like Tree2Thanks
  • 1 Post By Plato
  • 1 Post By biffboy

Math Help - Why is this the answer???

  1. #1
    Newbie
    Joined
    Apr 2012
    From
    Birmingham, Alabama
    Posts
    2

    Why is this the answer???

    I can't for the life of me figure out why 2 2/5 is the answer to the following question. If anyone can explain this to me then I would appreciate it.

    Question:

    John can paint a fence by himself in 6 hours and Jenny can paint the fence in 4 hours. How long will it take them to paint the fence if they work together?

    The answer is 2 2/5.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor

    Joined
    Aug 2006
    Posts
    18,959
    Thanks
    1783
    Awards
    1

    Re: Why is this the answer???

    Quote Originally Posted by Runfast1 View Post
    Question:
    John can paint a fence by himself in 6 hours and Jenny can paint the fence in 4 hours. How long will it take them to paint the fence if they work together? The answer is 2 2/5.
    \frac{1}{6}+\frac{1}{4}=\frac{5}{12}
    So in one hour they can do \left(\frac{5}{12}\right)^{th} of the fence.
    THUS??
    Thanks from Runfast1
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Senior Member
    Joined
    Mar 2012
    From
    Sheffield England
    Posts
    440
    Thanks
    76

    Re: Why is this the answer???

    In 1 hour John alone can paint 1/6 of the fence and Jenny can paint 1/4 of the fence. So together in 1 hour they can paint 1/6+1/4 of fence. That is 5/12 of fence. So 1/12 of fence in 1/5 hour and whole fence (12/12) in 12/5 hours.
    Thanks from Runfast1
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Newbie
    Joined
    Apr 2012
    From
    Birmingham, Alabama
    Posts
    2

    Re: Why is this the answer???

    Thank you so much for the very quick help!
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 5
    Last Post: March 3rd 2013, 08:17 PM
  2. Converting my answer into the books answer
    Posted in the Algebra Forum
    Replies: 6
    Last Post: March 10th 2011, 03:06 PM
  3. Replies: 1
    Last Post: October 4th 2010, 05:46 PM
  4. Replies: 3
    Last Post: April 6th 2008, 04:18 PM

Search Tags


/mathhelpforum @mathhelpforum