Question 840576: Five persons, A, B, C, D, E, are going to speak at a meeting. In how many orders can they take their turns if B must speak after A?
Answer by ewatrrr(24785)   (Show Source):
You can put this solution on YOUR website!
Hi,
Re reply: thanks for clarifying that Bill does not have to speak directly after A
A first: 24 ways (4!)
B first: N/A
C first: 12 ways
CA 3!, CB N/A, CD: CDA 2!, CDB N/A, CDEAB 1, CE: CEA 2!, CEB N/A, CEDAB 1
D first: 12 ways
E first: 12 ways
Five persons, A, B, C, D, E, are going to speak at a meeting.
In how many orders can they take their turns if B must speak after A? 4!
Think of AB as one Unit:
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