two pipes which can fill and imported tank in 12 hours and 15 hours are opened at 6:00 a.m. and 9:00 a.m. respectively on a certain day a leak situated at one fourth of the height of the tank that can empty the tank in 20 hours was observed to be open and at 2:00 p.m. and was immediately plugged.

Question : Pipes A, B and C can fill a tank in 20, 30 and 60 hours, respectively. Pipes A, B and C are opened at 7 a.m., 8 a.m., and 9 a.m., respectively, on the same day. When will the tank be full?

Option 1: 4:40 p.m.

Option 2: 5:40 p.m.

Option 3: 6:20 p.m.

Option 4: 7:20 p.m.

Question : Pipes A, B, and C can fill a tank in 15, 30 and 40 hours, respectively. Pipes A, B, and C are opened at 6 a.m., 8 a.m., and 10 a.m. on the same day. When will the tank be full?

Option 1: 3:20 p.m. 

Option 2: 11:20 p.m.

Option 3: 7:20 p.m.

Option 4: 5:20 p.m.

Question : A tank can be filled by pipe A in 2 hours and by pipe B in 6 hours. At 10 A.M., pipe A was opened. At what time will the tank be filled if pipe B is opened at 11 A.M.?

Option 1: 12.45 A.M.

Option 2: 5 P.M.

Option 3: 11.45 A.M.

Option 4: 12 P.M.

Question : Two taps P and Q can fill a tank alone in 10 hours and 12 hours respectively. If the two taps are opened at 9 a.m., then at what time should the tap P be closed to fill the tank at exactly 3 p.m.?

Option 1: 2 p.m.

Option 2: 1 p.m.

Option 3: 3 p.m.

Option 4: 12 p.m.

Question : Two pipes A and B can fill a tank in 12 hours and 18 hours, respectively. Both pipes are opened simultaneously. In how much time will the empty tank be filled completely?

Option 1: 9 hours 30 minutes

Option 2: 8 hours

Option 3: 7 hours 12 minutes

Option 4: 10 hours 24 minutes