[wheatley-blogs]

Remember factorials

like the things in math that were like

4! and it would be 4*3*2

yeah what was the point to that

why did we learn that

[post-cactus]

Analysis, man. Probability, permutations, combinations and shit.

nPr = n!/(n-r)! and nCr = n!/(r!(n-r)!)