Combinations
nCr
you have n items and how many ways are there to chose r of them
nCr=
remember than n! means n times all numbers before like
3!=3*2*1, 5!=5*4*3*2*1
9 stations, how many ways are there to chose 6 of them
9C6=
=
=
=
=
=
84
84 ways
nCr
you have n items and how many ways are there to chose r of them
nCr=
remember than n! means n times all numbers before like
3!=3*2*1, 5!=5*4*3*2*1
9 stations, how many ways are there to chose 6 of them
9C6=
84
84 ways