document.write( "Question 252632: A pump can empty a tank 4 times as fast as the other. If both pumps are working, they can complete the job in 3 hours. Find the rate of each pump. \n" ); document.write( "

Algebra.Com's Answer #184653 by drk(1908) $\"\"$ $\"About$

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This a job / time problem. Here is the formula\r
\n" ); document.write( "\n" ); document.write( "J1 / T1 * (together time) + J2 / T2 * (together time) = Total jobs.\r
\n" ); document.write( "\n" ); document.write( "Pump 2 does 1 job in x hours. So, J2 / T2 = 1/x.
\n" ); document.write( "Pump 1 does 1 job in 4x hours. So, J1 / T1 = 1/4x.
\n" ); document.write( "together time = 3
\n" ); document.write( "total jobs = 1 [1 tank].
\n" ); document.write( " $\"%281%2F4x%29%2A%283%29+%2B+%281%2Fx%29%2A%283%29+=+1\"$
\n" ); document.write( "---
\n" ); document.write( "step 1 multiply by 4x.
\n" ); document.write( " $\"1%2A%283%29+%2B+1%2A%283%29%2A%284%29+=+4x\"$
\n" ); document.write( "---
\n" ); document.write( "step 2 - solve for x.
\n" ); document.write( " $\"3+%2B+12+=+4x\"$
\n" ); document.write( "15 = 4X
\n" ); document.write( "X = 15/4 = 3.75 hours.
\n" ); document.write( "Pump 2 rate = 4/15 hours
\n" ); document.write( "pump 1 rate = 1/15 hours. \n" ); document.write( "

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