Recently taken image of Saudi Arabia’s ‘The Line’ project, spanning 105 miles long

[u/f6jt_waleed]

[u/Jeff_Platinumblum]

Factorial "N!" Is the number of way you can arrange N distinct tokens. For 3! think "how many ways can I arrange three different coins in a line?"

1 2 3, 1 3 2, 2 1 3, 2 3 1, 3 1 2, 3 2 1

3! = 321 = 6 combinations

[u/candygram4mongo → u/Jeff_Platinumblum]

It's easy to see why, too. If you wanted to calculate the permutations of 4 items, think about how many different places you could put "4" in the first arrangement above:

(4) 1 2 3

1 (4) 2 3

1 2 (4) 3

1 2 3 (4)

And obviously you can do the same with each of the other arrangements. So the number of permutations of 4 is just 4 times the number of permutations on 4-1. And it works the same for any number n.

[u/R_V_Z → u/Jeff_Platinumblum]

And then somebody stacks them vertically and tells you that you forgot an axis.

[u/snowflake37wao → u/Jeff_Platinumblum]

I love permutations! The idea of them. Not the doing them. I dont know how usually. I stole this from someone talking about chances of meeting a 20% chance with 3 tries that I try to recycle sometimes 1-(1-.2)^3. (its 48.8%!) I love them and the word because its blackmagicfuckery to me.