Isn't this assuming that 6 tosses means 6 or more? What if the SEVENTH (or more) toss(es) are heads? You must then discount the previous result. ('Thou shalt count to 6 - and 6 will be the count, 7 is too many, and eight is way out of it...etc.etc.) Surely you have to calculate based on the first 6 tosses are heads, and the seventh must be a tail, or alternatively from any given toss being a tail, the subsequent 6 being heads, then a tail, unless the 6th head is also the 20th toss. I'm sure someone can figure it out! > ---------- > From: Tracy Pierce[SMTP:[log in to unmask]] > Sent: Tuesday, February 29, 2000 4:12 PM > To: [log in to unmask] > Subject: Re: OT RE: Probability question > > Back to QCTerm, Wirt. The answer is 15 times .5**6, or .234375. > > > -----Original Message----- > > From: Gary Jackson [mailto:[log in to unmask]] > > Sent: Tuesday, February 29, 2000 2:03 PM > > To: [log in to unmask] > > Subject: OT RE: Probability question > > > > > > The one thing that I do know is that the probability of Wirt > > knowing the > > answer is 100%. > > > > G > > > > -----Original Message----- > > From: VANCE,JEFF (HP-Cupertino,ex1) [mailto:[log in to unmask]] > > Sent: Tuesday, February 29, 2000 1:17 PM > > To: [log in to unmask] > > Subject: OT: Probability question > > > > > > Hi all, > > > > (This is way off topic so please delete it now if you are not > > interested) > > > > My wife just took a biology test where one of the questions was: > > "What is the probability of tossing 6 heads in a row out of 20 coin > > tosses?" > > > > I believe that the number of tosses (20) doesn't matter. > > > > Thanks, > > Jeff > > >