document.write( "Question 258175: A water tank has an inlet pipe and a drain
\n" ); document.write( "pipe. A full tank can be emptied in 30 minutes if the drain
\n" ); document.write( "is opened and an empty tank can be filled in 45 minutes
\n" ); document.write( "with the inlet pipe opened. If both pipes are accidentally
\n" ); document.write( "opened when the tank is full, then how long will it take to
\n" ); document.write( "empty the tank?
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Algebra.Com's Answer #190044 by stanbon(75887)\"\" \"About 
You can put this solution on YOUR website!
A full tank can be emptied in 30 minutes if the drain
\n" ); document.write( "is opened and an empty tank can be filled in 45 minutes
\n" ); document.write( "with the inlet pipe opened. If both pipes are accidentally
\n" ); document.write( "opened when the tank is full, then how long will it take to
\n" ); document.write( "empty the tank?
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\n" ); document.write( "Filling tank DATA:
\n" ); document.write( "rate = 1/30 job/min
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\n" ); document.write( "Emptying tank DATA:
\n" ); document.write( "rate = 1/45 job/min
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\n" ); document.write( "Together DATA:
\n" ); document.write( "rate = 1/x job/min
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\n" ); document.write( "Equation:
\n" ); document.write( "rate - rate = together rate
\n" ); document.write( "1/30 - 1/45 = 1/x
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\n" ); document.write( "(45-30)/(30*45) = 1/x
\n" ); document.write( "15x = 30*45
\n" ); document.write( "x = 90 minutes (amt. of time needed to fill the tank)
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
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