remember that x! means times x ad all numbers below to 1
nCr
combiniations
out of n things, how many ways are there to choose r of them
nCr=[tex] \frac{n!}{r!(n-r)!} [/tex]
13 things choose 6
13C6=[tex] \frac{13!}{6!(13-6)!} [/tex]=
[tex] \frac{13!}{6!(7)!} [/tex]=
[tex] \frac{13*12*11*10*9*8}{6!} [/tex]=
[tex] \frac{13*12*11*10*9*8}{6*5*4*3*2*1} [/tex]=
[tex] \frac{13*2*11*2*3}{1} [/tex]=
1716 ways
