Question

an election ballot asks voters to select six city commissioners from a group of 15 candidates. in how many ways can this be done

Answer 1

n=total city commissioners r=how many candidates nCr=n!/[(n-r)!*r!] !=factoral
n=15 r=6
nCr=15!/[(15-6)!*6!]
nCr=1307674368000/362880(720)
nCr=1307674368000/261273600
nCr=5005