What is the answer 5 C 4?

what is 5 C 4 ?

$$\small{ \boxed{~~ \binom{n}k=\binom{n}{n-k}\qquad \text{ and } \qquad \binom{n}1 = n ~~}\qquad _5C_4 = \binom54 = \binom51 = 5 }$$

I have no idea.

$$_5C_4=\frac{5!}{4!(5-4)!}=5$$

.

You can enter it into this calc like this

nCr(5,4)

This is the output:

$${\left({\frac{{\mathtt{5}}{!}}{{\mathtt{4}}{!}{\mathtt{\,\times\,}}({\mathtt{5}}{\mathtt{\,-\,}}{\mathtt{4}}){!}}}\right)} = {\mathtt{5}}$$