# Introduction to Factorials

Do you have trouble organizing your desk? Are your bookshelves a disaster area? Well, you’re in luck! Act now, and get yourself a pack of factorials, designed to help you get your life in order! (Limit 2 per customer.)

 Language English Language Statistics Factorials

### Transcript

00:31

BECAUSE… THERE’S AN EXCLAMATION POINT AFTER MY NAME. IT’S KINDA MY THING.

00:35

Ah. Of course.

00:37

Tell you what – I’ll take it from here. SUIT YOURSELF.

00:40

A factorial, as my friend here mentioned, ends in an exclamation point.

00:44

However, the exclamation point – for once - is not being added for emphasis, or because

00:48

factorials are particularly exciting. HEY!

00:52

It is just a symbol which indicates that the number you are dealing with is, in fact, a

00:58

factorial.

00:58

For example, the number 4 factorial…

01:00

…really represents: “4 times 3 times 2 times 1.”

01:04

01:07

Say you’re going to see your favorite band Troll Slayer in concert.

01:10

The band is great… but they’ve only written four songs:

01:13

Deathtongue, Anvil of Evil, Scorpion Love, and Hate Shroud.

01:17

It isn’t tough to figure out what kind of music they’re going to play…

01:22

…but try figuring out in what order they will play their four songs.

01:27

We know you’ve got your fingers crossed that they open with Scorpion Love.

01:30

Then segue into Anvil of Evil, follow that puppy up with Hate Shroud, and finally bring

01:36

the house down with Deathtongue. But that’s only one possible set list. How

01:40

many possibilities are there?

01:41

Well, there are 4 options for their opener.

01:44

Once their first song has been determined, there are only 3 options for their second

01:48

song.

01:48

Then, only 2 options for their third…

01:50

…and lastly, a single option left for the big finale.

01:54

There are 4 times 3 times 2 times 1 – or 24 – possible orders for the band’s set

02:00

list.

02:03

Make sense? SURE! BUT WHAT IF THE AUDIENCE WANTS AN ENCORE?

02:06

I don’t think they’re ready for that kind of math.

02:09

GOOD CALL.

02:09

Blurb: Do you have trouble organizing your desk?

02:10

Are your bookshelves a disaster area? Well, you’re in luck! Act now, and get yourself

02:11

a pack of factorials, designed to help you get your life in order! (Limit 2 per customer.)