Question : An inlet pipe can fill an empty tank in 51 hours while an outlet pipe drains a filled tank in 76.5 hours. If both the pipes are opened simultaneously when the tank is empty, in how many hours will the tank get filled?

Option 1: 178.5

Option 2: 127.5

Option 3: 102

Option 4: 153

Question : Pipe X can fill a tank in 20 hours and pipe Y can fill the tank in 35 hours. Both the pipes are opened at alternate hours. If pipe Y was opened first, then how much time (in hours) does it take to fill the tank?

Option 1: $\frac{269}{11}$

Option 2: $\frac{286}{11}$

Option 3: $\frac{179}{7}$

Option 4: $\frac{172}{7}$

Question : Two pipes, X and Y, can fill a cistern in 24 minutes and 32 minutes, respectively. If both the pipes are opened together, then after how much time (in minutes) should Y be closed so that the tank is full in 18 minutes?

Option 1: 10

Option 2: 8

Option 3: 6

Option 4: 5

Question : Three pipes A, B, and C can fill a tank in 6 hours. After working together for 2 hours, C is closed and A and B fill the tank in 8 hours. The time (in hours) in which the tank can be filled by pipe C alone is:

Option 1: 10

Option 2: 12

Option 3: 8

Option 4: 9

Question : If two pipes function simultaneously, a tank is filled in 12 hours. One pipe fills the tank 10 hours faster than the other. How many hours does the faster pipe alone take to fill the tank?

Option 1: 20 hours

Option 2: 18 hours

Option 3: 15 hours

Option 4: 12 hours