document.write( "Question 970260: Working together, two pumps can drain a certain pool in 6 hours. If it takes the older pump 15 hours to drain the pool by itself, how long will it take the newer pump to drain the pool on its own? \n" ); document.write( "
Algebra.Com's Answer #592902 by josmiceli(19441)\"\" \"About 
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Add the pumping rates of the 2 pumps
\n" ); document.write( "to get their rate working together
\n" ); document.write( "Rate for older pump:
\n" ); document.write( "[ 1 pool drained ] / [ 15 hrs ]
\n" ); document.write( "Rate for newer pump:
\n" ); document.write( "[ 1 pool drained ] / [ t hrs ]
\n" ); document.write( "Rate working together:
\n" ); document.write( "[ 1 pool drained ] / [ 6 hrs ]
\n" ); document.write( "----------------------------
\n" ); document.write( "\"+1%2F15+%2B+1%2Ft+=+1%2F6+\"
\n" ); document.write( "Multiply both sides by \"+30t+\"
\n" ); document.write( "\"+2t+%2B+30+=+5t+\"
\n" ); document.write( "\"+3t+=+30+\"
\n" ); document.write( "\"+t+=+10+\"
\n" ); document.write( "The newer pump can drain the pool in
\n" ); document.write( "10 hrs working on it's own
\n" ); document.write( "-------------------------
\n" ); document.write( "check:
\n" ); document.write( "\"+1%2F15+%2B+1%2Ft+=+1%2F6+\"
\n" ); document.write( "\"+1%2F15+%2B+1%2F10+=+1%2F6+\"
\n" ); document.write( "\"+2%2F30+%2B+3%2F30+=+5%2F30+\"
\n" ); document.write( "\"+2+%2B+3+=+5+\"
\n" ); document.write( "\"+5+=+5+\"
\n" ); document.write( "OK
\n" ); document.write( "
\n" ); document.write( "
\n" );