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Answer : 3 28 Explanation : Answer: C) 28 Explanation: Three persons A, B, C can be arranged in a queue in six different ways, ie ABC, CBA, BAC, CAB, BCA, ACB. But since there are only 3 persons ahead of C, so C should be in front of the queue. Thus, there are only two possible arrangements, ie CBA and CAB. We may consider the two cases as under:Case I:  ←3C↔8B↔5A→21 Clearly, number of persons in the queue = (3 1 8 1 5 1 21=) 40 Case II:  ←3C A↔5B Number of persons between A and C                   = (8 - 6) = 2   ∵[C↔8B A→21B] Clearly number of persons in the queue = (3 1 2 1 21) = 28 Now, 28