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Homework Help: Word problem

  1. Sep 9, 2004 #1
    A can do a piece of work in 4 days and B in 6 days. How long will they require working together ?

    Hint. 1/4 + 1/6 = 1/x


    I just don't get them :redface: ( The problem and the hint).
    Can you help me understand it ?
     
  2. jcsd
  3. Sep 9, 2004 #2
    one peice of work in four days plus one peice of work in six days equals one peice of work in x days
     
  4. Sep 9, 2004 #3

    Fredrik

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    Question: Suppose A and B are eating potato chips from the same bag. It would take A 4 minutes to eat all the chips if B wasn't there. It would take B 6 minutes to eat all the chips if A wasn't there. How long will it take the two of them to finish that bag of chips?

    Hint: In one minute, A eats 1/4 of the chips and B 1/6 of the chips, so 1/4+1/6 of the bag will be eaten each minute. If they keep eating for x minutes, they will have eaten (1/4+1/6)x of the bag. The bag will be empty when this equals 1, so all you have to do is to solve the equation (1/4+1/6)x=1.
     
  5. Sep 9, 2004 #4

    Thank you very very very very much. :smile:
     
  6. Sep 9, 2004 #5
    Fredrik posted a very pedagogical hint :
    Suppose A and B are eating potato chips from the same bag. :rofl: :rofl:
    Doubtlessly students must pay more attention to potato chips than to abstract pieces of work.
     
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