In combination terms, why is it n choose n-r?
I don't know exactly what formula you're looking at, but my guess is that it has something to do with the fact that n choose r is equal to n choose n-r.
Off-topic discussion. Wanna talk about corsets, duct tape, or physics? This is the place. Detailed discussion of any current-season TV must be whitefonted.
In combination terms, why is it n choose n-r?
I don't know exactly what formula you're looking at, but my guess is that it has something to do with the fact that n choose r is equal to n choose n-r.
Timelies all!
Happy Birthday DX!
We have bought furniture. Ok, to be precise, we have ordered furniture and put a down payment on it.We bought a china cabinet and a bedroom set consisting of two night tables, a door chest and a headboard/frame for the bed. Whee.
Happy Birthday, DX. Is it a big one?
I found a $20 bill just now walking across campus. But I'm wondering if it's a fake. It's crisp and new and has the Big Head, but on the back in the empty field there are lots of little yellow "20"s floating around. I suspect it's real and looks fake, wwhich is just wrong.
Okay, I'm done with probability for the moment, but now I need to do individual cases of Fermat's Last Theorem, and I feel totally unworthy!
Thank you for the birthday wishes, everyone. I appreciate it.
Hey! Happy birthday, you!
Happy birthday, DX!!!! May this be your happiest year yet (until next year)!
Happy B-day, DX!
DX is timeless.
HAPPY BIRTHDAY, BEST OF DXes!
Do other mammals have navels? And if not, as appears to be the case, how does that work?