Well,
Since the students are mixed randomly (as mentioned in the problem), the
chances (probability) that the 'i' th student who comes out is ranked best
so far is directly (1/i). Since this is an independent Random Variable, the
answer thus becomes sum_1^n {1/i} which for large value of n can be
approximated to log (n).Hence the answer. On Mon, Nov 22, 2010 at 3:54 PM, shiva <shivanand.kadwad...@gmail.com>wrote: > > Any explanation of how it works and how you got log(69) as answer. > > Thanks in advance. > > > On Nov 22, 2:27 pm, Salil Joshi <joshi.sali...@gmail.com> wrote: > > Hi, > > The puzzle needs to be rephrased as: > > "If the rank of the student who comes out of the classroom is better > > than ranks of all students who came out before him/her, then he/she > > gets a lollipop". > > Rephrased this way, this is a famous puzzle, and the answer is > > log(69). > > > > On Nov 22, 12:44 pm, shiva <shivanand.kadwad...@gmail.com> wrote: > > > > > If all the person got his rank increased except the first(he is last > > > know) then > > > > > 1. if the previous first ranked person stand front in queue then 69 > > > lollipop need to be distributed. > > > 2. other case 68 lollipop need to be distributed. > > > > > On Nov 21, 9:46 pm, Shiv Shankar Prajapati <mca.shivshan...@gmail.com> > > > wrote: > > > > > > Its total no. of Student i.e. 69. > > > > If all the students ranking is increased then all the student will > get > > > > the lollipop. But there is one student left who was at top n now on > the > > > > least ranking and as the condition is given that student may appear > first > > > > and get the lollipop. So professor need will give 69 lollipop. in > this > > > > (worst) case. > > > > > > On Sun, Nov 21, 2010 at 8:42 PM, Ashim Kapoor <ashimkap...@gmail.com> > wrote: > > > > > Do you mean if the rank of a student is better than the rank of the > prev > > > > > student then he/she gets a lollipop? > > > > > > > Thank you, > > > > > Ashim > > > > > > > On Sun, Nov 21, 2010 at 6:57 PM, vamsee marpu < > marpu.vam...@gmail.com>wrote: > > > > > > >> Does anybody know the solution for the following problem : > > > > > > >> *A headmaster of a primary school performs an activity with the > students > > > > >> of a class to encourage them to perform better in academics. He > asks them to > > > > >> stand in queue, starts calling the students out one by one and > asks them > > > > >> their rank in class. Each one has a unique rank in class. If the > rank of a > > > > >> student is better than his/her previous best rank, then he awards > him/ her a > > > > >> lollipop (students love lollipops). Note that the first one in the > queue > > > > >> will always get a lollipop and the students arrange themselves in > random > > > > >> order in the queue. What is the expected number of lollipops the > headmaster > > > > >> will have to distribute among students if the total number of > students in > > > > >> the class is 69? Note that the answer can be a fractional number.* > > > > > > >> Thanks and Regards, > > > > >> M. Vamsee > > > > > > >> -- > > > > >> You received this message because you are subscribed to the Google > Groups > > > > >> "Algorithm Geeks" group. > > > > >> To post to this group, send email to algoge...@googlegroups.com. > > > > >> To unsubscribe from this group, send email to > > > > >> algogeeks+unsubscr...@googlegroups.com<algogeeks%2bunsubscr...@googlegroups.com> > <algogeeks%2bunsubscr...@googlegroups.com<algogeeks%252bunsubscr...@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 algoge...@googlegroups.com. > > > > > To unsubscribe from this group, send email to > > > > > algogeeks+unsubscr...@googlegroups.com<algogeeks%2bunsubscr...@googlegroups.com> > <algogeeks%2bunsubscr...@googlegroups.com<algogeeks%252bunsubscr...@googlegroups.com> > > > > > > > . > > > > > For more options, visit this group at > > > > >http://groups.google.com/group/algogeeks?hl=en. > > > > > > -- > > > > With Regards, > > > > > > Shiv Shankar, > > -- > You received this message because you are subscribed to the Google Groups > "Algorithm Geeks" group. > To post to this group, send email to algoge...@googlegroups.com. > To unsubscribe from this group, send email to > algogeeks+unsubscr...@googlegroups.com<algogeeks%2bunsubscr...@googlegroups.com> > . > For more options, visit this group at > http://groups.google.com/group/algogeeks?hl=en. > > -- -------- Thanks & Regards Salil Joshi. CSE MTech II, IITB A-414, Hostel 12 +91.9819.442.865 This is a confidential E-Mail. If it has reached you by mistake or if you are not the intended receiver, please send it back to me. -- You received this message because you are subscribed to the Google Groups "Algorithm Geeks" group. To post to this group, send email to algoge...@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.
