SOLUTION: One pipe can empty a tank in 8 hours and a second pipe can empty the same tank in 6 hours. If the first pope operated alone for two hours and then the second pipe is put into opera

Question 837171: One pipe can empty a tank in 8 hours and a second pipe can empty the same tank in 6 hours. If the first pope operated alone for two hours and then the second pipe is put into operation, how many hours after the second pipe is opened will the tank be empty?
Answer by josgarithmetic(39630) (Show Source): You can put this solution on YOUR website!
Job completion as a uniform rates situation could be sorted using rate, time, job; in the same way as travel situations of rate, time, distance.

The rate is as unit of "tanks emptied per hour", time is hours, and the job identified is, "emptying the tank". The unknown time during which the second pipe operates is t.

Pipe ID__________rate___________time____________job
firstpipe________1/8____________2+t____________
secondpipe_______1/6____________t______________

Find expressions for the contributed amount of job of each pipe:

Pipe ID__________rate___________time____________job
firstpipe________1/8____________2+t____________(1/8)(2+t)
secondpipe_______1/6____________t______________(1/6)t
TOTAL____________________________________________1

The needed equation is the sum of the amounts of the job that the pipes had done, and this sum is ONE WHOLE JOB, or 1.
EQUATION:
Solve for t.
-
-
LCD is 24.

hours
RELATED QUESTIONS
one pipe can empty a tank in 8 hours and a second pipe can empty the same tank in 6... (answered by richwmiller)

A pipe can fill a tank in 3 hours. Another pipe can empty the tank in 6 hours. If the... (answered by josmiceli)

An inlet pipe can fill a tank in 3 hours. An outlet pipe can empty the tank in 6 hours. (answered by Alan3354)

pipe A can fill an empty water tank in 3hours, while pipe B can fill the same tank in 6... (answered by ikleyn)

one pipe can empty the tank in 4 hours. a second pipe takes 2 hours to do the same job.... (answered by nerdybill)

Water can be pumped into or out of a tank via pipes A, B, and C. Pipe A can fill the tank (answered by Edwin McCravy)

Pipe A can fill a tank in 14 hours. Pipe B can empty a tank in 10 hours. Miscommunication (answered by stanbon)

A tank can be filled by one pipe in four hours and by a second pipe in six hours; and... (answered by Alan3354,josmiceli)

One pipe can fill a tank in 6 hours and another pipe can fill the same tank in 3 hours. A (answered by macston)