Posted by Alexus on September 7, 2006, at 1:37:19
In reply to Re: A math puzzle, posted by finelinebob on September 6, 2006, at 21:36:53
> There is a systematic way. It's called a Combination. Cominations can either allow for repetition or not, but since it doesn't matter what order the dx's are presented we'll do it without.
okely dokely
> (in other words, if it mattered that you were BP I THEN ADD, and that was different than ADD THEN BP I, we'd need to include repetition).order of presentation of symptoms doesn't matter. just which are present or absent. i think i'm following you...
> General formula is n!/[k!(n-k)!.!
> 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=5, and the result would be 9!/[5! (9-5)!]
!
(i'm a lot lost)
> If you don't know what that "!" means, it's a factorial. 3! = 3*2*1 = 6. 0! is defined as 1.okayyyyyyyyyy.
> Your problem is that you have more than one combination. 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.okay.
i'm really very stupid when it comes to math...thanks very much.
!
;-)
poster:Alexus
thread:683578
URL: http://www.dr-bob.org/babble/social/20060901/msgs/683877.html