document.write( "Question 437413: A small pipe can fill an oil tank in 6 min more time than it takes a larger pipe to fill the same tank. Working together both pipes can fill a tank in 4 min. How long would it take each pipe working alone to fill the tank? \n" ); document.write( "

Algebra.Com's Answer #302609 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"t\"$ = time for larger pipe to fill oil tank
\n" ); document.write( "given:
\n" ); document.write( " $\"+t+%2B+6+\"$ = time for smaller pipe to fill tank
\n" ); document.write( "---------
\n" ); document.write( "Add their rates of filling to get rate working together
\n" ); document.write( " $\"+1%2Ft+%2B+1%2F%28t%2B6%29+=+1%2F4+\"$
\n" ); document.write( "Multiply both sides by $\"+4t%2A%28t%2B6%29+\"$
\n" ); document.write( " $\"+4%2A%28t+%2B+6%29+%2B+4t+=+t%2A%28t%2B6%29+\"$
\n" ); document.write( " $\"4t+%2B+24+%2B+4t+=+t%5E2+%2B+6t+\"$
\n" ); document.write( " $\"+t%5E2+-+2t+-+24+=+0+\"$
\n" ); document.write( " $\"+%28t-6%29%2A%28t%2B4%29+=+0+\"$
\n" ); document.write( "The solutions are
\n" ); document.write( " $\"t+=+-4\"$ (can't use negative time)
\n" ); document.write( " $\"t+=+6\"$
\n" ); document.write( "and
\n" ); document.write( " $\"+t+%2B+6+=+12\"$
\n" ); document.write( "The smaller pipe takes 12 min
\n" ); document.write( "The larger pipe takes 6 min \n" ); document.write( "

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