GMAT Prep?? (Probablitiy)-Jill

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GMAT Prep?? (Probablitiy)-Jill

by dferm » Sun May 04, 2008 11:21 am
Jill, who lives in City C, plans to visit 3 different cities, M, L, and S. She plans to visit each city exactly once and return to City C after the 3 visits. She can visit the cities in any order. In how many different orders can she visit the 3 cities?

A. 3
B. 6
C. 8
D. 9
E. 12

Please explain...

Got this question right by doing it the long way. but would like to see it done a little smoother..

thanks.

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by moneyman » Mon May 05, 2008 1:44 am
Is the answer 6??
Maxx

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by dferm » Mon May 05, 2008 5:16 am
YES

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by ajguerre » Mon May 05, 2008 7:11 am
This is essentially a permutation problem. Think of the problem as: "In how many ways can I arrange the order of the 3 cities". You can also rephrase it to follow the "chairs" analogy: "How many different seat arrangements can you have with 3 chairs and 3 individuals"

The answer is 3! = 3*2*1 = 6