Recent content by who_

Well, not every time; but it happens frequently, and I actually don't know how to delete posts in PF.

Hmm, in that case, could it be my relatively slow internet connection?

I'm using Chromium on Debian 6. Perhaps I am double clicking sometimes - does that actually cause the post to appear twice?

You shouldn't merely give the answer - next time, try to lead the OP toward the correct solution. :)

Hi all, Upon rereading the problem, I realized I completely misunderstood the question. Not only did I miss the part that the boxes have to be completely filled up, I also realized that there are 15 kinds of books, not that there are merely 15 identical books. Sorry for the confusion. ><

Hi all, Upon rereading the problem, I realized I completely misunderstood the question. Not only did I miss the part that the boxes have to be completely filled up, I also realized that there are 15 kinds of books, not that there are merely 15 identical books. Sorry for the confustion. ><

Hi all, Upon rereading the problem, I realized I completely misunderstood the question. Not only did I miss the part that the boxes have to be completely filled up, I also realized that there are 15 kinds of books, not that there are merely 15 identical books. Sorry for the confusion. ><

Ummm, sure - but the original problem states that the books are indistinguishable - so your method doesn't work.

Can you show how you arrive at that answer? I do not get such a large answer (I also assume that the bins are indistinguishable - I don't know if that is a valid assumption or not).

Could you clarify? Do you have 2 different books? Or 15 books that are of two kinds? If so, how many of each?

That is clearly not right. So if one had 4 books, you are saying that the answer is 4! = 24? By calculating 15!/11!, you are treating each book differently. Thus, the actual question is how many bins have k books where k is between 1 and 4, inclusive.

Recently, many of my posts are being sent twice. Meaning, every time I click post, my post gets posted twice. Is anyone else having this problem?

I say this should be moved to the Precalculus help page... Anyhow... :) Well, for a start, your statement is NOT true. Consider {6,10,15}. Then gcd (6,10,15) = 1, but gcd(6,10) = 2, gcd(6,15) = 3, and gcd(10,15) = 10. Try solving it for n = 3. See if that gives you any ideas on how to...

What have you done so far? Please show your work so that we may know where you got stuck. If you are asking us to do the problem for you, then I'm afraid that is not allowed in this forum.

Well, WLOG assume that m <= n. If AD = Im, then what does that say about A? That means for any m-dimensional vector b, there is an n-dim vector x such that Ax = b (since one can choose x = Db). What does that say about the number of pivot rows of A? If CA = In, that means for any n-dimensional...