Results 1 to 4 of 4

Math Help - Inverse Proportion. explanation needed

  1. #1
    Newbie
    Joined
    Jun 2011
    Posts
    2

    Inverse Proportion. explanation needed

    Hi im studying for an exam and i have lost my sheet explaining how to do inverse proportion.

    I have the question: A farmer has enough grain to feed 50 cattle for 10 days. He sells 10 cattle. For how many days will the grain last now?

    The first time i went through i got the answer 12.5 days and i now do not know how to get back to that answer.

    Thanks in advance.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Flow Master
    mr fantastic's Avatar
    Joined
    Dec 2007
    From
    Zeitgeist
    Posts
    16,948
    Thanks
    5
    Quote Originally Posted by Boredom View Post
    Hi im studying for an exam and i have lost my sheet explaining how to do inverse proportion.

    I have the question: A farmer has enough grain to feed 50 cattle for 10 days. He sells 10 cattle. For how many days will the grain last now?

    The first time i went through i got the answer 12.5 days and i now do not know how to get back to that answer.

    Thanks in advance.
    There are (10)(50) = 500 units of grain.

    500/40 = 12.5 => 12.5 days.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Jun 2011
    Posts
    2
    Hmm so simple.

    Thanks
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor
    Joined
    Dec 2009
    Posts
    3,120
    Thanks
    1
    Quote Originally Posted by Boredom View Post
    Hi im studying for an exam and i have lost my sheet explaining how to do inverse proportion.

    I have the question: A farmer has enough grain to feed 50 cattle for 10 days. He sells 10 cattle. For how many days will the grain last now?

    The first time i went through i got the answer 12.5 days and i now do not know how to get back to that answer.

    Thanks in advance.
    Alternatively, it will take 50 cattle 10 days to eat the grain.
    Imagine they all munch away at the same rate, even after the 10 were sold.

    Take an intermediate step...
    It will take one of them 50 times as long to eat all the grain, that's 500 days.
    How long will it take 40 of them ?
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. [SOLVED] Inverse proportion/Direct proportion question
    Posted in the Statistics Forum
    Replies: 3
    Last Post: September 26th 2011, 07:22 AM
  2. Function of F(X) Explanation needed.
    Posted in the Algebra Forum
    Replies: 7
    Last Post: January 13th 2011, 11:08 AM
  3. Algebra Explanation Needed
    Posted in the Algebra Forum
    Replies: 2
    Last Post: August 31st 2010, 02:55 AM
  4. Big O - Explanation needed
    Posted in the Discrete Math Forum
    Replies: 22
    Last Post: August 9th 2009, 03:23 AM
  5. Multiplication explanation needed
    Posted in the Algebra Forum
    Replies: 3
    Last Post: July 7th 2009, 10:46 AM

Search Tags


/mathhelpforum @mathhelpforum