SOLUTION: A tank can be filled by an inlet pipe in 7 hours. While a drain pipe can empty the tank in a matter of 11 hours. If for the first four hours, the drain pipe was left open while the

Algebra ->  Rate-of-work-word-problems -> SOLUTION: A tank can be filled by an inlet pipe in 7 hours. While a drain pipe can empty the tank in a matter of 11 hours. If for the first four hours, the drain pipe was left open while the      Log On


   



Question 907733: A tank can be filled by an inlet pipe in 7 hours. While a drain pipe can empty the tank in a matter of 11 hours. If for the first four hours, the drain pipe was left open while the inlet pipe was filling it , how much longer would it have taken the inlet pipe to fill the tank full if the tank was emptied at the start?
Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
4/7-4/11+x/7=1
44/77-28/77+11x/77=77/77
it filled about a fifth with inlet and outlet opened
44-28+11x=77
16+11x=77
11x=61
x=61/11
x= 5 6/11=5.5454545454545454545454545454545 more hours after the 4