COS 341 - Handouts


Handout Number 2
September 17, 1997

Homework Set 1

Written Assignments Read Chapter 1, Chapter 3.

Written Assignments Do Exercises 3, 4, 7, 12, 22, 28 in Section 1.8.

Special Problem 1 (to be counted as 2 exercises) In class, we demonstrated that for the Monte-Hall Problem the switch'' strategy is better than the non-switch''. Give a precise mathematical description of the probability space, the event of winning a holiday in each strategy, and compute the probability for the event (for each strategy). (The answers should be 2/3 and 1/3 for the two strategies.)

Hint One can take as Universe the set of all triplets tex2html_wrap_inline25 where tex2html_wrap_inline27 represent, respectively, the door Monte chooses to hide the Holidays,'' the door the contestant picks, and the ``Donkey'' door Monte shows to the contestant.

Special Problem 2 (to be counted as 2 exercises; you may use the computer if you wish) Let tex2html_wrap_inline31 be the number of candidates in the Hiring Problem. Let tex2html_wrap_inline33 be the probability of hiring the best candidate under strategy k''. (a) What's the optimum k to use (in the sense of maximizing tex2html_wrap_inline33 )? What's the value of this optimum tex2html_wrap_inline33 (accurate to three digits)? (b) Give a rigorous proof that this is the optimum k to use. (This part is harder.)




Rebecca L. Davies
Thu Sep 18 10:31:28 EDT 1997