If pipes A and B can fill the tank separately in 3 hours and 4 hours respectively while pipe C can now empty the completely filled tank in 1 hour due to more leakages. If the pipes A, B and C are opened in order at 9, 10 and 11 AM respectively, at what time will the tank be empty ?

5 : 12 AM 12 : 48 PM 12 : 12 PM 1 : 12 PM

1 : 12 PM