Saturday Bonus Puzzler

Re: Saturday Bonus Puzzler

Henry Higginbotham

The answer hit me as I went down the list to see which three of the five I had to choose from. D'oh!

That's the answer I got

Alex Y

Thanks for confirming.

An aha! puzzle masquerading as a probability puzzle.

A wrench in the works

Henry Higginbotham

Suppose your friend, anticipating your offer of a wager, had said that three of the first six presidents had died on July 4th. That's just as true and, to my ear, even more likely to make you think that number six had to be in the set.

On the other hand, what if your friend responded with, "No, but I'll take it if you can name one of the first four." (With the original assertion of "three of the first five.") On its face this sounds like better odds for you, but wouldn't it be worse (assuming, of course, that your friend isn't sneaky, as in the first scenario)?

Re: A wrench in the works

Alex Y

Suppose your friend, anticipating your offer of a wager, had said that three of the first six presidents had died on July 4th.

I'll give you ten to one odds that my friend was not that devious, nor was he anticipating my bet. But that is why this is a "real life" puzzle, not one of certainty or calculable odds.

On the other hand, what if your friend responded with, "No, but I'll take it if you can name one of the first four." (With the original assertion of "three of the first five.")

I'd reply "I'll bet on that, but only two-to-one odds." And I would guess Washington. MUCH less confident of the answer to this one. If he were not one of the five, "three of the first five" is still much easier to say than "after Washington, three of the next four".

On its face this sounds like better odds for you, but wouldn't it be worse

Yes. 2/4 = 50% chance vs 3/5 = 60% chance (real-world considerations aside).

PS

Alex Y

I haven't verified the claim made in the puzzle, nor the result of either my original bet or the one I made in response to Henry's "wrench" post.

Re: PS

Alex Y

Just looked it up, and what do you know--I would have lost the second bet. Good thing I lowered the odds!

It was Adams, Jefferson, and Monroe, with Adams and Jefferson being on the same day, 7/4/1826

Click and Clack confirmed

Alex Y

the answer Henry gave, with one of the brothers raising the same hypothetical objection. Their wording of the original problem addressed that though, in that the friend said "I read that 3 of the first 5..." Having read it in a different source even further removes the possibility that the 3/5 was a ruse to draw in a bettor.

Hmmm . . . now I'm wondering

Henry Higginbotham

Now I'm wondering if I'd heard that one back when it was originally broadcast, although I still don't recall it.