Question

A club has 12 members. In how many ways can we select four members to go on a trip?

Answer 1

this is the number of combinations of 4 from 12

12C4   =        12!
                 ----------
                  4! 8!

=    12*11*10*9             11*5*9  =  495
      --------------     = 
        4*3*2*1