Man, I feel so stupid. Yes, it is a case of conditional probability. We have to calculate the probability of six heads, "given" that 5 heads have occured. So answer is 17/18.
On Tue, Aug 9, 2011 at 1:47 AM, Arun Vishwanathan <aaron.nar...@gmail.com>wrote: > @shady: 3/5 can be the answer to such a question: what is prob of getting > head on nth toss if we have 4 coins fair and one biased...then at nth toss u > choose 4/5 1/5 prob and then u get 3/5 > > @shady , don: i did this: P( 6th head | 5 heads occured)= P( 6 heads )/ P( > 5 heads) > > answr u get is 17/18..i cud be wrong please correct if so > > > On Mon, Aug 8, 2011 at 10:45 PM, shady <sinv...@gmail.com> wrote: > >> answer is 3/5. 17/80 is the answer for 6 consecutive heads. >> >> >> On Tue, Aug 9, 2011 at 2:07 AM, Don <dondod...@gmail.com> wrote: >> >>> 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. >>> >>> >> -- >> 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. >> > > > > -- > "People often say that motivation doesn't last. Well, neither does > bathing - that's why we recommend it daily." > > -- > 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. > -- Shuaib http://www.bytehood.com http://twitter.com/ShuaibKhan -- 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.
