Vicky goes for a 7-day trip in Country X. There are four cities, A, B, C and D, in the country.Each day Vicky visits one city, and she will not visit the same city on two
consecutive days.Given that Vicky visits City A on both Day 1 and Day 7, how many different possible itineraries are there for her 7-day trip?
A maths competition question.2
2010-11-06 5:42 am
回答 (1)
2010-11-06 6:35 am
✔ 最佳答案
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2010-11-05 22:35:47 補充：
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