SOLUTION: In how many ways can a sample (without replacement) of 4 items be selected from a population of 15 items?

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Question 1083970: In how many ways can a sample (without replacement) of 4 items be selected from a population of 15 items?
Answer by ikleyn(52797) About Me  (Show Source):
You can put this solution on YOUR website!
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C%5B15%5D%5E4 = 15%21%2F%284%21%2A%2815-4%29%21%29 = 12%21%2F%284%21%2A11%21%29 = %2815%2A14%2A13%2A12%29%2F%281%2A2%2A3%2A4%29 = 1365 ways.


C%5Bn%5D%5Ek = n%21%2F%28k%21%2A%28n-k%29%21%29 is the number of combinations of n items taken "k" at a time.

On combinations, read the lessons
    - Introduction to Combinations
    - PROOF of the formula on the number of Combinations
    - Problems on Combinations
in this site.

Also, you have this free of charge online textbook in ALGEBRA-II in this site
    - ALGEBRA-II - YOUR ONLINE TEXTBOOK.

The referred lessons are the part of this online textbook under the topic "Combinatorics: Combinations and permutations".