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My thought
A guest can not have wine and dessert at the same time. So waiter have to go to separate room at one time. Thus at the first time slot, there at 3 possibility (one of 3 room will not be served). At second time slot, the room not served last time must be served, thus there are two possibility this time ( one of two that served last time can be served again). At third round, only one choice left. So now the possobility of going to rooms are 2*3=6
For each room, either wine or desert can be choose first, so there are 2*2*2=8 posibilitys. Thus
The total possibility should be 6*8=48, otherwise, the statement of the problem must have something missed |
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