Question : A water tank can be filled by a tap in 30 minutes and another tap can fill it in 60 minutes. If both the taps are kept open for 5 minutes and then the first tap is closed, how long will it take for the remaining tank to be full?

Option 1: 20 minutes

Option 2: 25 minutes

Option 3: 30 minutes

Option 4: 45 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

Question : Taps A and B can fill a tank in 15 minutes and 10 minutes, respectively while tap C can empty the full tank in x minutes. If all three taps are opened together, the tank is filled completely in 8 minutes. Tap C alone will empty $\frac{3}{8}$ th part of the tank in:

Question : A tap can fill a cistern in 40 minutes and a second tap can empty the filled cistern in 60 minutes. By mistake without closing the second tap, the first tap was opened. In how many minutes will the empty cistern be filled?

Question : Pipes P and Q can fill a tank in 18 and 27 minutes, respectively, whereas pipe R can empty the full tank in 54 minutes. P and Q were opened together for 6 minutes and then closed and R was opened. The tank was emptied by R alone in:

Question : Two taps A and B can fill a tank in 10 hours and 12 hours respectively. If the two taps are opened at 10 AM, at what time (in PM) should tap A be closed to fill the tank at exactly 4 PM?