Question

How do you evaluate 6C3?

Answer 1

`""^6C_3=20`

Explanation:

`""^nC_r` is selection of `r` possible combinations of objects from a set of `n` objects.

Mathematically `""^nC_r=(n!)/(r!xx(n-r)!)`

Hence `""^6C_3=(6!)/(3!xx(6-3)!)`

= `(6xx5xx4xx3xx2xx1)/((3xx2xx1)xx(3xx2xx1))`

= `(6xx5xx4)/(3xx2xx1)=5xx4=20`