SOLUTION: there are 13 students in a club. how many was can four students be selected to attend a conference

Algebra ->  Permutations -> SOLUTION: there are 13 students in a club. how many was can four students be selected to attend a conference      Log On


   

Question 759135: there are 13 students in a club. how many was can four students be selected to attend a conference
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
n C r = (n!)/(r!(n-r)!)

13 C 4 = (13!)/(4!*(13-4)!)

13 C 4 = (13!)/(4!*9!)

13 C 4 = (13*12*11*10*9!)/(4!*9!)

13 C 4 = (13*12*11*10)/(4!)

13 C 4 = (13*12*11*10)/(4*3*2*1)

13 C 4 = (17160)/(24)

13 C 4 = 715

There are 715 ways to select the students.