document.write( "Question 820898: Together, two pipes can fill a tank in 3 hours. If the smaller pipe takes 7 hours to fill the tank, how long does it take the larger pipe to fill the tank? \r
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Algebra.Com's Answer #493759 by josmiceli(19441) $\"\"$ $\"About$

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Together, the rate of fil;ling is:
\n" ); document.write( "( 1 tank filled ) / ( 3 hrs )
\n" ); document.write( "The rate of filling of the smaller pipe is:
\n" ); document.write( "( 1 tank filled ) / ( 7 hrs )
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\n" ); document.write( "Let $\"+t+\"$ = the time in hrs for the larger pipe
\n" ); document.write( "to fill the tank
\n" ); document.write( "Add the rates of filling of the 2 pipes:
\n" ); document.write( " $\"+1%2Ft+%2B+1%2F7+=+1%2F3+\"$
\n" ); document.write( "Multiply both sides by $\"+21t+\"$
\n" ); document.write( " $\"+21+%2B+3t+=+7t+\"$
\n" ); document.write( " $\"+4t+=+21+\"$
\n" ); document.write( " $\"+t+=+5.25+\"$ hrs
\n" ); document.write( " $\"+.25%2A60+=+15+\"$ min
\n" ); document.write( "It will take the larger pipe 5 hrs and 15 min
\n" ); document.write( "to fill the tank\r
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