13 Triskaidekaphobia

2013 Happy New Year

Triskaidekaphobia - FEAR of the number 13

What's with the number 13?

Why is it often an unlucky number?

Hotels missing 13 room, or even 13th floor (not sure about that, but heard the rumor)

(figuring this is a number topic, it seemed good enough that it didn't need to go to DT)

Yeah, dice, only go to 12. (x2) (normal casino dice). Six sides is nice an even box shape though.

Quote: rxwine

What's with the number 13?

Why is it often an unlucky number?

Several times, I posted the same puzzle in this forum. That puzzle claimed that people originally believed that Friday the 13th was unlucky because they thought the 13th of the month occurs more often on Friday than any other day of the week. The question was two-part:

(a) Does the 13th really occur most often on Friday or not?
(b) Prove your answer to part (a).

The first few times I posted the puzzle, no one seemed up to the challenge. I was annoyingly persistent, so eventually the Wizard gave it a try. He posted this comment afterward.

Quote: Wizard

So I hope you're happy, I just got back from vacation, have a ton of catching up to do, and I've spent much of the day on this.

He did eventually get the correct answer and proof, of course.

Quote: Doc

(a) Does the 13th really occur most often on Friday or not?

No.

Quote:

(b) Prove your answer to part (a).

Who, me?

But according to Isaac Asimov's short story titled, coincidentally, "Friday the Thirteenth," there can be only a maximum of 3 Friday 13ths in a given year, and there has to be at least one every year. If you want proof, read the story (it can be found in "More Tales of the Black Widowers")

Like most folks, Nareed, you missed part (a), so I won't worry about your not providing the part (b) proof of your incorrect answer.