arithmetic - two pipes can fill a tank in 8 and 12 hours respectively where as escape pipe can empty it in 6 hours if the three pipes are opened at 3pm 4 pm and 5 pm respectively at what time will the tank be filled - skillgun

Solution: Required time be x hours and given the three pipes are opened in the time interval of 1 hour each.
.'. (x/8 + (x-1)/12) - (x -2/6) = 1.
(6x +4x-4)/48 -(x- 2)/6 = 1.
2x+12 = 48
=> x = 36/2
=> x = 18 hours.
Hence, the tank will filled at 3 P.M + 18 = 9 A.M.