#### thelazyman

##### Junior Member

- Joined
- Jan 14, 2006

- Messages
- 58

How many groups consisting of at least 2 people can be chosen from a group of 10 people?

I tried...

10!/2!2!2!2!2! Thinking that 5 groups can be formed but got the wrong answer.

- Thread starter thelazyman
- Start date

- Joined
- Jan 14, 2006

- Messages
- 58

How many groups consisting of at least 2 people can be chosen from a group of 10 people?

I tried...

10!/2!2!2!2!2! Thinking that 5 groups can be formed but got the wrong answer.

- Joined
- Jan 29, 2005

- Messages
- 8,259

I am not doing this completely. Here are hints.thelazyman said:How many groups consisting of at least 2 people can be chosen from a group of 10 people?

‘Groups’ in this context are subsets!

If there are N elements in a set, then there are 2<SUP>N</SUP> subsets of that set.

Now one of those sets is the empty set - the null-group no members.

There are N singletons set, subsets with only one element.

Now you combine those along with what you learned from the dice problem and finish it this off. Post your answer and we will check it.

G

is it 2^10 - 10?

- Joined
- Jan 29, 2005

- Messages
- 8,259

Actually it is \(\displaystyle \LAnonymous said:is it 2^10 - 10?

2^{10} - 11\)

Think about why 11!

G

total - 1 - 0

2^10 -10 -1

cool, thanks

2^10 -10 -1

cool, thanks