Question

Suppose there are 9 people (named A-I)

How many different ways can they be grouped into 5?

How many different ways can they be grouped into 5 if A must be included?

Answer 1

1) Different ways they grouped into 5 ways that is 5 choosen out of 9 in 9C5 ways =126,

Where C =Combination

2) different ways can they be grouped into 5 if A must be included then 4 can be choosen ( as A befirw select) out of 8 (except A) in 8C4 =70

Solution file is attached go through it

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