SOLUTION: An Olympic sized pool can be filled by pipe a in 18 hours and pipe b in 12 hours.there is also a drain pipe that drains the entire pool in 8 hours. if the values of pipe a and pipe

Algebra ->  Rate-of-work-word-problems -> SOLUTION: An Olympic sized pool can be filled by pipe a in 18 hours and pipe b in 12 hours.there is also a drain pipe that drains the entire pool in 8 hours. if the values of pipe a and pipe      Log On


   



Question 1064590: An Olympic sized pool can be filled by pipe a in 18 hours and pipe b in 12 hours.there is also a drain pipe that drains the entire pool in 8 hours. if the values of pipe a and pipe b and the drain pipe are open how long will it take to fill the pool? round to the nearest tenth of an hour if necessary.
rate, time, fraction of job

Found 2 solutions by josgarithmetic, ikleyn:
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
%281%2F18%2B1%2F12-1%2F8%29%28pool%2Fhour%29

The reciprocal of that is what the question asks for.




Time to FILL the pool using all pipes open, 72 hours.

Answer by ikleyn(52777) About Me  (Show Source):
You can put this solution on YOUR website!
.
The pipe A fills 1%2F18 of the pool volume per hour.

The pipe B fills 1%2F12 of the pool volume per hour.

The pipe C drains 1%2F8 of the pool volume per hour.

When all 3 pipes work, they fill 1%2F18+%2B+1%2F12+-+1%2F18 = 1%2F72 of the pool volume per hour.

Hence, it will take 72 hours to fill the pool if all 3 pipes are open.

For a wide variety of similar solved joint-work problems with detailed explanations 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
in this site.

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".