document.write( "Question 1208990: A 5-horsepower (hp) pump can empty a pool in 5 hours.A smaller, 2-hp pump
\n" ); document.write( "empties the same pool in 8 hours. The pumps are used together to begin emptying
\n" ); document.write( "this pool.After two hours, the 2-hp pump breaks down. How long will it take the
\n" ); document.write( "larger pump to empty the pool?
\n" ); document.write( "Let hp = horsepower
\n" ); document.write( "5hp = 1/5
\n" ); document.write( "2hp = 1/8
\n" ); document.write( "Let t = time in hours
\n" ); document.write( "1/t = time it takes larger pump to empty the pool
\n" ); document.write( "My equation is:
\n" ); document.write( "(1/5) + (1/8) = 1/t
\n" ); document.write( "Is this correct?
\n" ); document.write( " \n" ); document.write( "

Algebra.Com's Answer #847797 by MathTherapy(10552) $\"\"$ $\"About$

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document.write( "A 5-horsepower (hp) pump can empty a pool in 5 hours.A smaller, 2-hp pump empties the same pool in 8 hours. The pumps are used together to begin emptying this pool.After two hours, the 2-hp pump breaks down. How long will it take the larger pump to empty the pool?\r\n" );
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document.write( "Let hp = horsepower\r\n" );
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document.write( "5hp = 1/5 \r\n" );
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document.write( "2hp = 1/8\r\n" );
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document.write( "Let t = time in hours \r\n" );
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document.write( "1/t = time it takes larger pump to empty the pool\r\n" );
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document.write( "My equation is:\r\n" );
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document.write( "(1/5) + (1/8) = 1/t\r\n" );
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document.write( "Is this correct? \r\n" );
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document.write( "No. That's WRONG.\r\n" );
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document.write( "Yes, the rates are . However, both worked TOGETHER, for 2 hours, so fraction of job completed in 2 hours = \r\n" );
document.write( "And, since the SLOWER pump broke down and the FASTER completed the job, the FASTER completed the remaining fraction:\r\n" );
document.write( ", with T being the time taken by the FASTER to complete the job.\r\n" );
document.write( "Both fractions SUM to 1, so equation is actually: \r\n" );
document.write( "Solve that now for T, the time it takes the LARGER/FASTER to complete the job.

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