Sixth toss is independent of previous tosses and dependent only on coin selection...!
1/5 + 4/5(1/2)= 3/5 is the correct answer.... we want to calc. probability of getting heads the sixth time only.... even if it would have been 100 th time...3/5 would be the answer only.. On 8/8/11, Prakash D <cegprak...@gmail.com> wrote: > 1.) coin is fair > 2.) coin is unfair > > P(head) for unfair coin= 1/5 * 1= 1/5 > P(head) for fair coin= 4/5* 1/2 = 2/5 > > > the probability at any instant that the tossed coin is a head is 3/5 > > 17/80 is the probability to get head at all the six times. > > the soln. for this problem will be 3/5 > > On Mon, Aug 8, 2011 at 12:45 AM, aseem garg <ase.as...@gmail.com> wrote: > >> If the coin is unbiased then probability of heads: 1/2 irrespective of >> whether it is first time or nth time. So answer should be 3/5. >> Aseem >> >> >> >> On Mon, Aug 8, 2011 at 12:39 AM, saurabh chhabra >> <saurabh131...@gmail.com>wrote: >> >>> Even u dont get why u people are gettin 17/80...the probability that >>> it will be a head 6th time will be same as the frst time...so it shud >>> be 3/5... >>> >>> On Aug 7, 11:05 pm, Kunal Yadav <kunalyada...@gmail.com> wrote: >>> > @algo: We can get head in two cases:- >>> > >>> > 1.) coin is biases >>> > 2.) coin is not biased >>> > >>> > P(head) for biased= 1/5 *1*1*1*1*1*1= 1/5 >>> > P(head) for unbiased= 4/5*(1/2)^6 >>> > hence combined probability is what nitish has already mentioned. Hope >>> you >>> > get the point. >>> > >>> > >>> > >>> > >>> > >>> > >>> > >>> > >>> > >>> > On Sun, Aug 7, 2011 at 11:29 PM, Algo Lover <algolear...@gmail.com> >>> wrote: >>> > > Can anyone explain the approach how to solve this . >>> > > I think all tosses are independent so it should be 3/5. why is this >>> in- >>> > > correct >>> > >>> > > On Aug 7, 10:55 pm, saurabh chhabra <saurabh131...@gmail.com> wrote: >>> > > > sry...its wrong >>> > >>> > > > 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 >>> > Kunal Yadav >>> > (http://algoritmus.in/) >>> >>> -- >>> 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. >> > > -- > 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.
