Monday

January 26, 2015

January 26, 2015

Posted by **Eleanor** on Thursday, February 19, 2009 at 6:28pm.

How many subsets of S have at most 4 elements?

This question is from the section in my book called "Counting Partitions: Combinations." I would greatly appreciate any help! Thanks!

- Math -
**drwls**, Thursday, February 19, 2009 at 7:19pmIt seems to me there are 10 ways to pick subsets of 1 element; 10!/(8! 2!)= 45 subsets with 2 elements; 10!/(7!3!) = 120 with three elements and 10!/(6!4!) = 210 subsets with four elements

The total is 385.

- Math -
**Eleanor**, Thursday, February 19, 2009 at 8:29pmHey, thanks! However, that answer was not right. Any other ideas? You seem to be on the right track... This problem really confuses me.

- Math -
**Eleanor**, Thursday, February 19, 2009 at 9:37pmOk, the answer is 386! Yay! However, I am not sure why the answer is not 385.... maybe because we had to add c(10,0) into the mix. Thanks so much for the help... I wouldn't have gotten the answer had it not been for your help!

**Answer this Question**

**Related Questions**

Combinations - Assume that the set S has 10 elements. How many subsets of S have...

Finite MAth - Assume that the set S has 7 elements. How many subsets of S have ...

math - Assume that the set S has 14 elements. How many subsets of S have at most...

math - Let Pn be the set of all subsets of the set [n]={1,2,…,n}. If two ...

Math(combinations) Help - Let Pn be the set of all subsets of the set [n]={1,2...

Math - How many subsets of a set with 100 elements have more than one element? ...

math - For the set X={m,n.p,q,r,s}, let R be the relation on P(X) (power set) ...

math - for a set of three elements find the number of different subsets of 2 ...

Math - I'm new to this but.. how many subsets does a five element have. How many...

math - how many nonempty subsets does a set with ten elements have... my ...