counting techniques

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counting techniques

by iamnikkilarin » Wed Aug 15, 2012 4:41 am
A sales representative for a company must visit 6 different cities
exactly one time each. In how many different orders can the
cities be visited?

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by Brent@GMATPrepNow » Wed Aug 15, 2012 6:14 am
iamnikkilarin wrote:A sales representative for a company must visit 6 different cities
exactly one time each. In how many different orders can the
cities be visited?
Here we want to arrange 6 unique items (cities) in a row.

In general, we can arrange n unique objects in n! ways.

So, the total number of ways to arrange 6 cities is 6!, which equals [spoiler]6x5x4x3x2x1 = 720[/spoiler]

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Brent
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