SOLUTION: Working together, two pumps can drain a certain pool in 3 hours. If it takes the older pump 12 hours to drain the pool by itself, how long will it take the newer pump to

Algebra ->  Rate-of-work-word-problems -> SOLUTION: Working together, two pumps can drain a certain pool in 3 hours. If it takes the older pump 12 hours to drain the pool by itself, how long will it take the newer pump to       Log On


   

Question 1117256: Working together, two pumps can drain a certain pool in
3
hours. If it takes the older pump
12
hours to drain the pool by itself, how long will it take the newer pump to drain the pool on its own?
Do not do any rounding.

Found 2 solutions by ikleyn, stanbon:
Answer by ikleyn(52847) About Me  (Show Source):
You can put this solution on YOUR website!
.
Two pumps, working together, drain  1%2F3  of the tank volume per hour.


The older tank drains  1%2F12 of the tank volume per hour.


Hence, the newer pump drains  1%2F3 - 1%2F12 = 4%2F12-1%2F12 = 3%2F12 = 1%2F4  of the tank volume per hour.


Hence, it will take 4 hours for the newer pump to drain the tank working alone.

Solved.

            > > > Be aware:  The answer and the solution by the other tutor both are   I N C O R R E C T ! < < <

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It is a typical and standard joint work problem.

There is a wide variety of similar solved joint-work problems with detailed explanations in this site.  See the lessons
    - Using Fractions to solve word problems on joint work
    - Solving more complicated word problems on joint work
    - Selected joint-work word problems from the archive


Read them and get be trained in solving joint-work problems.

Also,  you have this free of charge online textbook in ALGEBRA-I in this site
    - ALGEBRA-I - YOUR ONLINE TEXTBOOK.

The referred lessons are the part of this textbook under the topic
"Rate of work and joint work problems"  of the section  "Word problems".


Save the link to this online textbook together with its description

Free of charge online textbook in ALGEBRA-I
https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson

to your archive and use it when it is needed.


Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Working together, two pumps can drain a certain pool in 3
hours. If it takes the older pump 12 hours to drain the pool by itself,
How long will it take the newer pump to drain the pool on its own?
Do not do any rounding.
--------
together rate = 1/3 job/hr
older pump rate = 1/12 job/hr
newer pump rate = 1/x job/hr
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Equation:
1/x + 1/12 = 1/3
------
12 + 3x = 4x
x = 12 hrs (time for the newer pump)
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Cheers,
Stan H.
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