Pipe A can fill a tank in 12 hours. Pipe B whose diameter is twice that of pipe A is also connected to the tank. If both the pipes are kept open when the tank is empty, how long will it take the tank to overflow?

(A)2 hours 40 minutes

(B)2 hours 12 minutes

(C)4 hous

(D)9 hours 36 minutes

(E)2 hours 24 minutes

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