SOLUTION: A tank can be filled by one pipe stream in 6 hours, and by another pipe stream in 4 hours. It can be emptied by third pipe stream in 7 hours. If the first pipe stream was opened tw

Algebra ->  Rate-of-work-word-problems -> SOLUTION: A tank can be filled by one pipe stream in 6 hours, and by another pipe stream in 4 hours. It can be emptied by third pipe stream in 7 hours. If the first pipe stream was opened tw      Log On


   



Question 354083: A tank can be filled by one pipe stream in 6 hours, and by another pipe stream in 4 hours. It can be emptied by third pipe stream in 7 hours. If the first pipe stream was opened two hours ahead of the second and third pipe streams, how long will it take to fill the tank?
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
first pipe = 6 hours
so it can do 1/6 of the job in 1 hour.
so in 2 hours it has done 1/3 of the of the job.
Balance job remaining = 1-1/3 = 2/3 of the job.
...
Time taken by three pipes to complete balance job
pipe 1- 4 hours
pipe 2- 8/3 hours
pipe 3 = 14/3 hours
...
1/4+3/8 -3/14 of the job they will do in 1 hour
0.41 of the job they do in1 hour.
1/0.41 hours they will take to do 2/3 of the job
=2.4 hours
+ 2hours (pipe one alone)
= 4.4 hours
...
m.ananth@hotmail.ca