Question 88720
in how many ways can you make a four-letter password from A, B, C, D, E if you are not allowed to repeat characters?
5 ways to select the 1st letter
4 ways to select the 2nd letter
3 ways to select the 3rd letter
2 ways to select the 4th letter
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Total # of ways = 5*4*3*2 = 120 passwords
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Another way to get the answer 5P4 = 5!/(5-4)!
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Cheers,
Stan H.