Posted by Alexus on September 7, 2006, at 6:44:11
In reply to Re: A math puzzle, posted by finelinebob on September 6, 2006, at 21:36:53
AAAHHHHHHHHHHH
I followed the link and tried to nut it out.
Messed up a lot.
>If you have 9 dx's and you need to find out how many combinations there are if you take them 5 at a time, then n=9, k=5Oops.
I was thinking n=2 (two possible truth values P and A) and k=9 (nine symptoms). Yeech. When I did stats for psychology they used to laugh at me because they said they never saw anyone make the errors I make. Its because of logic you see. They would give me things like 2X4X8X9X4 and I said I couldn't do it until they put the brackets in. It isn't a wff (well formed formula) without brackets, you see. But it goes like this, eh?:
{[(2X4)X8]X9}X4 (you do the stuff in the brackets first). Crap crap crap i'm crap at math :-(> Your problem is that you have more than one combination.
Ah, I see. I figured it would just tell me how many rows on the truth table... I didn't know how to go about getting rid of the rows with less than 5 P's...
You have these:
> n=9, k=5
> n=9, k=6
> n=9, k=7
> n=9, k=8
> n=9, k=9
> Add them all together and you get your answer.
> Oh. That would be 256.That makes sense (kinda semi sorta)
Thanks.:-)
poster:Alexus
thread:683578
URL: http://www.dr-bob.org/babble/social/20060901/msgs/683896.html