Consider the 5 * 64 possible outcomes for the selection of coin and six flips, each one happening with equal probability. Of those 320 possible outcomes, 4*62 are excluded by knowing that the first 5 flips are heads. That leaves 64 outcomes with the rigged coin and 2 outcomes with each of the fair coins, for a total of 72 outcomes. 68 of those are heads, so the answer to the puzzle is 68 of 72, or 17 of 18. Don
On Aug 8, 2:36 am, Shachindra A C <sachindr...@gmail.com> wrote: > @brijesh > > *first five times* is mentioned intentionally to mislead i think. I vote for > 3/5. Moreover, 17/80 doesn't make sense also. Plz correct me if I am wrong. > > > > On Mon, Aug 8, 2011 at 12:06 PM, sumit gaur <sumitgau...@gmail.com> wrote: > > (3/5) > > > On Aug 7, 10:34 pm, Algo Lover <algolear...@gmail.com> wrote: > > > A bag contains 5 coins. Four of them are fair and one has heads on > > > both sides. You randomly pulled one coin from the bag and tossed it 5 > > > times, heads turned up all five times. What is the probability that > > > you toss next time, heads turns up. (All this time you don't know you > > > were tossing a fair coin or not). > > > -- > > You received this message because you are subscribed to the Google Groups > > "Algorithm Geeks" group. > > To post to this group, send email to algogeeks@googlegroups.com. > > To unsubscribe from this group, send email to > > algogeeks+unsubscr...@googlegroups.com. > > For more options, visit this group at > >http://groups.google.com/group/algogeeks?hl=en. > > -- > Regards, > Shachindra A C -- You received this message because you are subscribed to the Google Groups "Algorithm Geeks" group. To post to this group, send email to algogeeks@googlegroups.com. To unsubscribe from this group, send email to algogeeks+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/algogeeks?hl=en.
