Lesson Combinations

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This Lesson (Combinations ) was created by by Shin123(626) About Me : View Source, Show
About Shin123: Just a kid who solves math problems for fun :)
Refer to Permutations if you’re not interested in combinations. Combinations are written 3 ways, nCr,C(n,r),and .

Problem 1



You won a game show and you get to pick 6 out of 13 prizes. How many ways are there to pick any 6?
Solution 1
There are C(13,6) ways to pick because picking prize A and then prize B is the same as picking prize B and then picking prize A. The formula is nCr=n%21%2Fr%21%28n-r%29%21 So there are
13%21%2F6%21%2813-6%29%21
13%21%2F6%21%287%21%29 There are 1716 ways to pick 6 prizes out of 13.

Problem 2



There are 8 letters in a bag. You grab 3 letters. How many combinations are there?
Solution 2
There are ways.
8%21%2F3%21%288-3%29%21
8%21%2F3%21%285%21%29 There are 56 ways.
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