document.write( "Question 910668: how could i salve this problem?.. supposable a small pump can empty a swimming pool in 60 hours and that a large pump can empty a pool in 20 hours. working together how long would it take to empty a pool? \n" ); document.write( "

Algebra.Com's Answer #552592 by josgarithmetic(39617) $\"\"$ $\"About$

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Very generally, two agents performing at rates 1/t and 1/T, so that the rate 1/T is for the small or slower, and 1/t is the rate for the faster bigger agent, then the combined rate for both agents working simultaneously on the same item will be the sum of their rates:\r
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\n" ); document.write( "\n" ); document.write( " $\"%281%2Ft%2B1%2FT%29\"$
\n" ); document.write( " $\"%281%2Ft%29%28T%2FT%29%2B%281%2FT%29%28t%2Ft%29\"$
\n" ); document.write( " $\"T%2F%28tT%29%2Bt%2F%28tT%29\"$
\n" ); document.write( " $\"highlight%28%28T%2Bt%29%2F%28tT%29%29\"$ \r
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\n" ); document.write( "\n" ); document.write( "I have used lower case, t, for the shorter amount of time and upper case T for the bigger amount of time; the slower the agent, the larger the time for it to do the 1 unit of the job. \n" ); document.write( "

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