Question 411257: A reading list contains 20 articles. How many ways are there to choose 3 articles from the list?
Answer by rfadrogane(214)   (Show Source):
You can put this solution on YOUR website! A reading list contains 20 articles. How many ways are there to choose 3 articles from the list?
Sol'n:
This problem is involving a combination,
so,N = nCr = n!/(n-r)!r!
n=20, r=3
N =C(20,3)= 1,140 ways ----answer
^_^
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