I'll give you a question, please answer with step-by-step reasoning process.
Pipes A and B can fill a cistern in 8 and 24 minutes respectively. They are opened an alternate minutes. Find how many minutes, the cistern shall be full?\nOptions:\n(A) 22\n(B) 12\n(C) 88\n(D) 99\n(E) 27

(B)
1/8 + 1/24 = 1/6\n6 * 2 = 12.

The final answer: (B)