# Latex Formula

• LaTeX

## Main Question or Discussion Point

How do you write the permutation and combination formulas using latex. This is the best I can do:

$$n_P_r=\frac{n!}{(n-r)!}$$

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cristo
Staff Emeritus
You mean like this: $$n \choose r$$ or $$^n\mathrm{C}_r$$ ?

Last edited:
Yes, that's what I meant, but I am used to writing down like this:

http://img88.imageshack.us/img88/7682/formula2nj1.png [Broken]

Last edited by a moderator:
cristo
Staff Emeritus
Ok, how about this then: $$_n\mathrm{C}_r \hskip5mm _n\mathrm{P}_r$$