Lesson Page

Math A

 

A  combination  is a set of objects in which order is not important.

 

 The formula:   

** Remember  n --> total
                       r --> want
                       ! --> factorial

 

                       
 Example:  Evaluate    7C2   =     7·6    =   42  =  21
                                                   2·1          2      

                               
                                                                                        

Example:       There are 12 boys and 14 girls in Mrs. Schultzkie's math class.  Find the number of ways Mrs. Schultzkie can select a team of  3 students from the class to work on a group project.  The team consists of  1 girl and 2  boys.     

boy     12C2                  girl    14C1

          12 ·11                        14
             2·1                           1

                   66      ·        14

                          =   924   

 


                      


Schultzkie