Question : Pipes A and B can fill a tank in 18 minutes and $22 \frac{1}{2}$ minutes, respectively while pipe C can empty the full tank in 12 minutes. A and B are opened together for 6 minutes and then closed. Now C is opened. C alone will empty the tank in ____.

Option 1: $5$ minutes

Option 2: $8 \frac{2}{5}$ minutes

Option 3: $7 \frac{1}{5}$ minutes

Option 4: $6$ minutes

Question : There are 3 taps, A, B, and C, in a tank. These can fill the tank in 10 h, 20 h, and 25 h, respectively. At first, all three taps are opened simultaneously. After 2 h, tap C is closed, and taps A and B keep running. After 4 h, tap B is also closed. The remaining tank is filled by tap A alone. Find the percentage of work done by tap A itself.

Option 1: 75%

Option 2: 52%

Option 3: 72%

Option 4: 32%

Question : Pipes A and B can empty a full tank in 18 hours and 24 hours, respectively. Pipe C alone can fill the tank in 36 hours. If the tank is $\frac{5}{6}$ full and all the three pipes are opened together, then in how many hours will the tank be emptied?

Option 1: $10 \frac{1}{2}$

Option 2: $12 \frac{1}{2}$

Option 3: $10$

Option 4: $12$

Question : Pipes A and B can fill an empty tank in 6 and 8 hours respectively, while pipe C can empty the full tank in 10 hours. If all three pipes are opened together, then the tank will get filled in:

Option 1: $4 \frac{4}{23}$ hours

Option 2: $6\frac{1}{5}$ hours

Option 3: $5\frac{5}{23}$ hours

Option 4: $7\frac{1}{2}$ hours

Question : Pipes A, B and C can fill a tank in 10, 15 and 30 hours, respectively. D is an emptying pipe which alone can empty the full tank in $x$ hours. A, B and C are opened together for 3 hours and then closed. Now D is opened which alone empties the tank in 30 hours. What is the value of $x$?

Option 1: 50

Option 2: 40

Option 3: 60

Option 4: 45