document.write( "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? \n" ); document.write( "
Algebra.Com's Answer #400990 by stanbon(75887)\"\" \"About 
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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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\n" ); document.write( "4 litre rate: 1/20 job/min
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\n" ); document.write( "6 litre rate: 1/12 job/min
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\n" ); document.write( "7 litre rate: 1/10 job/min
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\n" ); document.write( "Together rate: 1/x job/min
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\n" ); document.write( "Eqution:
\n" ); document.write( "rate + rate + rate = together rate
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\n" ); document.write( "1/20 + 1/12 + 1/10 = 1/x
\n" ); document.write( "Multiply thru by 60x to get:
\n" ); document.write( "3x + 5x + 6x = 60
\n" ); document.write( "14x = 60
\n" ); document.write( "x = 30/7 = 4.2857 minutes (time to do the job together
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
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