Docstoc

clubs

Document Sample
clubs Powered By Docstoc
					Alice   Bob   Celia Don    are members of a club.
                 Bob         In how many ways can they select
        Alice     Celia      a president and vice president ?
                  Don            4 x 3 = 12
                 Alice
        Bob        Celia
                  Don

                 Alice
         Celia    Bob
                 Don
                 Alice
         Don      Bob
                 Celia
Alice   Bob   Celia Don    are members of a club.
                 Bob           In how many ways can they select
        Alice     Celia        a 2 person committee?
                  Don
                                                   1.)
                 Alice
        Bob        Celia                           2.)
                  Don

                 Alice                             3.)
         Celia    Bob
                 Don                               4.)

                 Alice                             5.)
         Don      Bob
                 Celia                             6.)
Alice      Bob   Celia are running for pres., vice pres., and secretary
                 Bob        Celia
   Alice                                               There are 6
                 Celia      Bob                        different ways
                 Alice      Celia                      of arranging
   Bob                                                 3 people in
                                                       order.
                 Celia      Alice
                 Alice      Bob
   Celia

                 Bob        Alice

        The number of possible outcomes = 3 x 2 x 1 = 6
Alice   Bob    Celia Don      Edna     are members of a club.

   In how many ways can they select a pres., vice pres., and secretary?

 There are 5 ways     For each of the 5 ways          For each of the 20
 to select a pres.    to select a pres., there are    ways to select pres.
                      4 ways to select a vice pres.   and vice pres.,
                                                      there are 3 ways to
                                                      select a secretary.
        5 x 4 x 3 = 60
                               In how many ways can they select a
                               3 person committee?

Alice   Bob Celia Don   Edna


                                  There are 60 branches on this tree -
                                  60 ways to select 3 people in order



                                       But each 3 person committee
                                       is repeated 6 times on this
                                       list of 60.
                               In how many ways can they select a
                               3 person committee?

Alice   Bob Celia Don   Edna


                                This one committee appears 6 times
                               In how many ways can they select a
                               3 person committee?

Alice   Bob Celia Don   Edna


                                And this committee appears 6 times
Alice    Bob     Celia Don       Edna   are members of a club.



The number of ways of selecting
a pres., vice pres., and secretary       =      5x4x3

the number of repetitions of each
3 person committee                       =       3x2x1

 The number of 3 person committees = 5 x 4 x 3 = 10
                                     3x2x1

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:0
posted:1/16/2013
language:English
pages:8