Question 737439: "There are 6 books on a reading list. Students must read 3 of the books on the list. In how many different ways can a student select 3 books?" My teacher says the answer is 20 but how?
Answer by rothauserc(4718)   (Show Source):
You can put this solution on YOUR website! we are looking for the combinations of 6 books taken 3 books at a time...also note that the order of the selected books does not matter, that is, books 3,2,1 is the same as books 1,2,3
we use the combinations formula which says
the total combinations of 6 things take 3 at a time is
6! / ((3!) * (6-3)!) where ! stands for factorial
we have
6! / (3! * 3!) = 6*5*4 / 3*2 = 20 different ways 3 books can be selected
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