Question

How do you evaluate 8C2?

Answer 1

`28.`

Explanation:

We have, `""nC_r=(n!)/{(n-r)!r!}`

`:. ""8C_2=(8!)/{(8-2)!*2!}=(8!)/(6!*2!)=(6!*7*8)/(6!*2!)={cancel (6!)*7*8}/{cancel(6!)*2!}=56/(1*2)=28.`