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Question 636387: If it takes a 4 litre jerry can 20 mins to fill up a 1000 liter tank, 12 mins for a 6 liter jerry can to fill the same tank separately, and 10 mins for a 7 liter jerry can to fill the tank separately, how long will it take all together to fill the 1000 liter tank?
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! If it takes a 4 litre jerry can 20 mins to fill up a 1000 liter tank, 12 mins for a 6 liter jerry can to fill the same tank separately, and 10 mins for a 7 liter jerry can to fill the tank separately, how long will it take all together to fill the 1000 liter tank?
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4 litre rate: 1/20 job/min
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6 litre rate: 1/12 job/min
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7 litre rate: 1/10 job/min
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Together rate: 1/x job/min
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Eqution:
rate + rate + rate = together rate
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1/20 + 1/12 + 1/10 = 1/x
Multiply thru by 60x to get:
3x + 5x + 6x = 60
14x = 60
x = 30/7 = 4.2857 minutes (time to do the job together
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Cheers,
Stan H.
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