SOLUTION: f two inlet pipes are both open, they can fill a pool in 3 hours and 36 minutes. One of the pipes can fill the pool by itself in 6 hours. How long would it take the other pipe to f

Algebra ->  Equations -> SOLUTION: f two inlet pipes are both open, they can fill a pool in 3 hours and 36 minutes. One of the pipes can fill the pool by itself in 6 hours. How long would it take the other pipe to f      Log On


   

Question 1115198: f two inlet pipes are both open, they can fill a pool in 3 hours and 36 minutes. One of the pipes can fill the pool by itself in 6 hours. How long would it take the other pipe to fill the pool by itself?
Found 2 solutions by josgarithmetic, ikleyn:
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
(....)

1%2Fx%2B1%2F6=1%2F3%2636%2F60

1%2Fx%2B1%2F6=1%2F3%263%2F5

1%2Fx%2B1%2F6=1%2F%2818%2F5%29

1%2Fx%2B1%2F6=5%2F18
From here, multiply both sides by 18x, and simplify before finish solving...

Answer by ikleyn(52778) About Me  (Show Source):
You can put this solution on YOUR website!
.
3 hours and 36 minutes = 336%2F60 = 33%2F5 = 18%2F5 hours.


So, the first pipe fills  1%2F%28%2818%2F5%29%29 = 5%2F18 of the tank volume per hour.


The two pipes fill  1%2F6 of the tank volume per hour, according to the condition.


Hence, the second pipe fills  5%2F18 - 1%2F6  of the tank volume per hour,  which is equal to


          5%2F18 - 1%2F6  = 5%2F18 - 3%2F18 = 2%2F18 = 1%2F9 of the tank volume per hour.


It means that the second pipe will fill the tank in 9 hours.


Answer. It will take exactly 9 hours for the second pipe to fill the tank, working alone.


Any other answer is incorrect.

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It is a typical 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.


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The lesson to learn from this solution: 

    If you are given the combined rate of two participants and the rate of one of them, then the rate of the second

    participant is the difference of the two given rates.