So wise.
you are viewing a single comment's thread
view the rest of the comments
[–] 4 points 4 months ago (1 child)

factorials are mostly encountered in combinatorics, which is problems like, how many ways are there to put 3 objects of different colors in a row? well, the first can be any of the 3, the second can be either of the other 2, and the last is whichever 1 is left, so 3×2×1=3!=6

so how many ways are there to put 0 objects in a row? well there's 1, it's this one:

‎
‎

that's why 0!=1

  • source
  • parent
  • hideshow 1 child comment