document.write( "Question 925607: An inlet pipe can fill up the tank in 6 hours while an outlet pipe can empty the tank in 9 hours. One day, the tank was being filled. When it was 1/3 full, a boy opened the outlet pipe. How long did it take to fill the rest of the tank? \n" ); document.write( "

Algebra.Com's Answer #561616 by Edwin McCravy(20055) $\"\"$ $\"About$

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document.write( "These problems are like \"D=RT\" problems, except that the 'distance' is\r\n" );
document.write( "replaced by 'job to do', The 'job' here is 'one tank'.\r\n" );
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\n" ); document.write( "An inlet pipe can fill up the tank in 6 hours
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document.write( "So the inlet pipe's filling rate is \r\n" );
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\n" ); document.write( "while an outlet pipe can empty the tank in 9 hours.
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document.write( "The outlet's emptying rate is considered as a NEGATIVE filling rate.\r\n" );
document.write( "So the outlet pipe's NEGATIVE filling rate is\r\n" );
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\n" ); document.write( "One day, the tank was being filled. When it was 1/3 full, a boy opened the outlet pipe.
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document.write( "So the fraction of a job left to do is to fill  of a tankful.\r\n" );
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\n" ); document.write( "How long did it take to fill the rest of the tank?
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document.write( "Now the filling rate is the sum of the rates of the two pipes:\r\n" );
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document.write( " and the job is  of a tank.\r\n" );
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document.write( "Just as in \"D=RT\" problems we use \"TIME=DISTANCE/RATE\" we use here \r\n" );
document.write( "\"TIME=JOB/RATE\".  The job is  of a tank and the rate is \r\n" );
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document.write( "So,\r\n" );
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document.write( "Edwin

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