SOLUTION: Jonathan can type a 20 page document in 40 minutes, susan can type it in 30 minutes, and Jack can type it in 24 minutes. Working together, how much time will it take them to type
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Question 419350: Jonathan can type a 20 page document in 40 minutes, susan can type it in 30 minutes, and Jack can type it in 24 minutes. Working together, how much time will it take them to type the same document? Found 2 solutions by stanbon, josmiceli:Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! Jonathan can type a 20 page document in 40 minutes, susan can type it in 30 minutes, and Jack can type it in 24 minutes. Working together, how much time will it take them to type the same document?
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Jonathan rate: 1/40 job/min
Susan rate:: 1/30 job/min
Jack rate:: 1/24 job/min
Together rate:: 1/x job/min
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Equation:
rate + rate + rate = together rate
1/40 + 1/30 + 1/24 = 1/x
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Multiply thru by 120x to get:
3x + 4x + 5x = 120
12x = 120
x = 10 minutes (time for them to do the job together)
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Cheers,
Stan H.
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You can put this solution on YOUR website! Add their rates of typing is Jonathan's rate ( 1 document/40 min) is Susan's rate (1 document/30 min) is Jack's rate (1 document/24 min)
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Let = the time in minutes with all 3 working together
Multiply both sides by
Multiply both sides by
It will take them 10 min working together
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