Three pipes \(A, B,\) and \(C\) are attached to a tank. Pipe \(A\) alone can fill the empty tank in \(6\) hours, pipe \(B\) alone can empty the full tank in \(8\) hours and pipe \(C\) alone can fill the empty tank in \(12\) hours. At \(9\) am pipe \(A\) is opened. One hour after that pipe \(B\) is opened and one hour from that pipe \(C\) is opened. At what time the tank will be full?

A. 11:40 am
B. 12:27 pm
C. 1:40 pm
D. 5 pm
E. 5:20 pm

Answer: E

Source: e-GMAT