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Dr. Shapiro's Puzzle of the Day

Today's Puzzle

Wednesday, September 30
I was recently taking a walk at the edge of town when I saw a home with a banner out front that said

 SLOW! NO WAKE! 

A minute later, I saw another one! As it happens, there was something else unusual about these homes (and it's not that they were occupied by cavemen trying to ensure uninterrupted naps for their babies). What was unusual about them?

   


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Yesterday's Puzzle + Solution

Taxonomy is the grouping of species according to shared traits. For example, mammals are generally warm-blooded, nurse their young, and have hair. Some taxonomic rules have exceptions; if you think mammals don't lay eggs, the platypus would like to have a word with you.

A junior taxonomist, with knowledge of animals confined to what she can glean from her favorite poster (see above), might infer that mammals can mostly be distinguished from non-mammals according to what rule? This rule has no basis in biology, but it correctly classifies 22 of the 26 animals as drawn by the artist.

Hint #1: The animals the rule gets wrong are... ... the alligator, fox, monkey, and whale.

Hint #2: For those who still can't see... Stop being such a mammal!

Solution With the noted exceptions, all the mammals are shown with their eyes closed, and the non-mammals with their eyes open.

I first noticed this on my daughter's bathmat, which has the same art (except for a different fox, for who knows what reason). I don't suppose the artist was conscious of it, but they seem to have different ideas about how to make a mammal look cute and how to make a reptile/amphibian/fish/bird/echinoderm look cute!

Congratulations to yesterday's full and partial solvers Summer, Anna J., Anna K., Yana, and Mrs. Gregg. 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 June 2020.