document.write( "Question 206797This question is from textbook Elementary and Intermediate Algebra
\n" ); document.write( ": Filling a tank. A water tank has an inlet pipe and a drain pipe. A full tank can be emptied in 30 minutes if the drain is opened and an empty tank can be filled in 45 minutes with the inlet pipe opened. If both pipes are accidentally opened when the tank is full, then how long will it take to empty the tank? \n" ); document.write( "
Algebra.Com's Answer #156330 by ptaylor(2198)\"\" \"About 
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Let x=amount of time it takes to empty the tank when both pipes are left open
\n" ); document.write( "Then, with both pipes open ,the tank empties at the rate of 1/x tank per min\r
\n" ); document.write( "\n" ); document.write( "Drain pipe empties at the rate of 1/30 tank per min
\n" ); document.write( "Inlet pipe fills at the rate of 1/45 tank per min
\n" ); document.write( "Then, with both pipes open ,the tank empties at the rate of 1/30-1/45 tank per min \r
\n" ); document.write( "\n" ); document.write( "So, our equation to solve is
\n" ); document.write( "1/30-1/45=1/x multiply each term by 90x
\n" ); document.write( "3x-2x=90
\n" ); document.write( "x=90 min------------------amount of time to empty tank when both pipes are left open\r
\n" ); document.write( "\n" ); document.write( "CK\r
\n" ); document.write( "\n" ); document.write( "In 90 min, inlet pipes pours in 90(1/45) or 2 tanks of water
\n" ); document.write( "In 90 min, drain pipe drains 90(1/30) or 3 tanks of water
\n" ); document.write( "So the two tanks of water poured in by the inlet pipe in 90 min plus the full tank that was already there equals the 3 tanks that were emptied by the drain pipe.\r
\n" ); document.write( "\n" ); document.write( "Hope this helps---ptaylor \n" ); document.write( "
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