document.write( "Question 909520: I have tried doing quite a few of these but the example in the book is different, please help me!\r
\n" ); document.write( "\n" ); document.write( "An inlet pipe on a swimming pool can be used to fill the pool in 15 hours. The drain pipe can be used to empty the pool in 24 hours. If the pool is 1/4 filled and then the inlet pipe and drain pipe are opened, how long from that time will it take to fill the pool?
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Algebra.Com's Answer #551894 by richwmiller(17219)\"\" \"About 
You can put this solution on YOUR website!
We subtract for the drain pipe.
\n" ); document.write( " We are doing 3/4 of the job since the pool is 1/4 filled\r
\n" ); document.write( "\n" ); document.write( "x/15-x/24=3/4
\n" ); document.write( "x/15-x/24=3/4
\n" ); document.write( "24x/360-15x/360=3/4
\n" ); document.write( "8x/120-5x/120=3/4
\n" ); document.write( "3x=3/4*120
\n" ); document.write( "3x=3*30
\n" ); document.write( "x=30 hours
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\n" ); document.write( "10/15-10/24=3/4
\n" ); document.write( "720/360-450/360=3/4
\n" ); document.write( "240/360-150/360=1/4
\n" ); document.write( "90/360=1/4
\n" ); document.write( "1/4=1/4
\n" ); document.write( "ok\r
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