Questions

How many different committees of 7 people can be formed from a group of 10 people?

How many different committees of 7 people can be formed from a group of 10 people?

Choose 1 of 10, then 1 of 9, etc
–> 10*9*8*7*6*5*4 = 604800
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But, choosing A,B,C,D,E,F,G is the same as A,C,D,E,F,G,B. There are 7*6*5*4*3*2*1 ways to choose any group of 7, = 5040 ways.

604800/5040 = 120 different committees.
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= 10!/7!