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Dr. Shapiro's Puzzle of the Day

Today's Puzzle

Monday, April 5
Ivanov, Ibáñez, Di Giovanni, Hovanessian, Ioannou, Yahyaoğlu, Mac Seáin, and Ben Yochanan are surnames from around the world that are equivalent to what very common last name in English?

   


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Yesterday's Puzzle + Solution

Each of the following brands is known for one very specific category of product. Can you tell me what those items are? (To make this more than a pure name-recognition quiz, I've provided some hints.)
  1. Melitta
    Hint Your parents probably have some of these in a cabinet. When in use, they are approximately conical.

  2. Zildjian
    Hint You might see a Zildjian product on stage—at a concert or a comedy show.

  3. Hagoromo
    Hint This brand is highly coveted by mathematicians.

Solution Melitta invented the paper coffee filter and is still the most recognizable brand; Zildjian has been making cymbals for 400 years; and Hagoromo is the original maker of a popular brand of blackboard chalk.

Congratulations to yesterday's solvers Zoe, Zach Z., Leo S., Trent, Inca, Dr. Yetman, Graham, and especially Connor who got all three. Thanks to everybody who made a guess!

About This Site

Though he now teaches mathematics, Dr. (né Mr.) Shapiro's first job in a K–12 school was as a lunch monitor in Davis, CA. It was there that he originated the Puzzle of the Day, even rewarding correct answers with tickets in denominations like "15 points" (though without a clear idea of how he'd ultimately redeem these). Dr. Shapiro's favorite puzzle from this pre-professional era was "Tell me the location of the beehive on this campus."

Ten years later, Dr. Shapiro revived Puzzle of the Day at Proof School, writing each day's puzzle on a name tag. After 600 puzzles or so, he was just starting to feel normal about students reading his chest all the time when campus closed and the puzzle, like the rest of our lives, moved online. New puzzles are posted daily on school days.

Want to catch up on old PotDs? There's an archive currently containing puzzles from March to December 2020.