Tuesday, November 1, 2011

#305 / Puzzler Solutions









Back on 1/11/11 I posed a calendar puzzler, asking this:

For the current century (just starting from 1-1-11) how many days will there be where the date can be expressed (in the calendar style I have employed here) by repetitions of the same number, no other number appearing in the date?
The answer, the way I count it, is 13.

Actually, I was hoping that some "numerate" friend would be able to provide a kind of "formula." I am not strong in what the British call "maths," though I guess I can count with the best of them.

And....speaking of the best of them, the winner is Pamela Flick. Here's her listing, provided almost immediately at 4:29 p.m. on 1/11/11:
1-1-11 / 1-11-11 / 11-1-11 / 11-11-11 / 2-2-22 / 2-22-22 / 3-3-33 / 4-4-44 / 5-5-55 / 6-6-66 / 7-7-77 / 8-8-88 / 9-9-99.
That does count up to 13. As Pamela said, and as I say, too: "What did I miss? :)"

Someone also sent me an email completely without reference to my "Puzzler" question, claiming that there is something particularly unusual about the year 2011. First, there are those "nothing but ones" dates, as already noted: 1/1/11; 1/11/11; 11/1/11; and 11/11/11.

Then, just to embellish the theme, if you take the last two digits of the year in which you were born, and add the age you will be this year, the result will be 111 for everyone! That's the claim, anyway, and it does work for me.

Finally, October had five Sundays this year; and five Mondays; and five Saturdays, too. That's unusual! According to the information I was sent, this only happens once every 823 years, with years like these being called "Moneybags." Are we feeling rich, now? Let's ask the good folks at Occupy Wall Street

Tim Goncharoff also responded to my puzzler question, but he came up with only 11 dates, and the listing above does have a couple more!!


2 comments:

  1. Make it 14 instances! You may add 12/12/12 to the list.

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  2. Ah, Anonymous! Your comment points to the problem that happens so often in human communication: it's hard to say what you mean, exactly, when you have to use words!

    In this case, there was an unclarity in the "rules" of the puzzle, which I restate below, for convenience. I said that I was looking for dates that were formed by "repetitions of the same number, no other number appearing in the date." I should have used the word "digit."

    "12," of course is a "number," but it's not the kind of "number" I had in mind, and that I illustrated in articulating the rules for the puzzle (again, see below). So, in terms of what I "meant," I don't think the number "12" qualifies, but I admit that there was a definite ambiguity in what I actually "said," and maybe even a flat misstatement.

    Since "10" is also a "number," if that kind of "number" qualifies, then the correct answer would be "15," not "14" or "13."

    HERE ARE THE RULES as I (ambiguously) stated them: "For the current century (just starting from 1-1-11) how many days will there be where the date can be expressed (in the calendar style I have employed here) by repetitions of the same number, no other number appearing in the date?"

    I think that what I said, strictly speaking, does include both "12," and "10." But it's not what I "meant."

    My father often told me, when I was growing up, to "listen to what I mean, not what I say." He implied the fault was in me; here, I think the fault really was - for not saying what I meant more clearly.

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