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Letter Permutation/Probability

Sequences, counting (including probability), logic and truth tables, algorithms, number theory, set theory, etc.
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hakandragon
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Letter Permutation/Probability

Postby hakandragon » Sat Nov 14, 2009 9:47 pm

If someone could help me out with this, I would be so grateful. I've always been bad with these word/letter questions. Is there just a simple formula I can follow?

A five-letter permutation of the letters of the word CLUBS is selected at random. The probability that the second letter is C and the last letter is B is what?
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stapel_eliz
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Postby stapel_eliz » Sat Nov 14, 2009 11:43 pm

How many permutations are there, in total?

If you fix the two named letters at the named positions, how many letters remain to be placed? In how many ways can you do this placement?

Divide the second number by the first number to find the probability of the second situation. :wink:
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