13 May 2007

Concerning gifts (and other puzzles)

What can you conclude from the following three premisses?

  1. If something is not gift-wrapped, it's not a gift.
  2. Nothing that's gift-wrapped is entirely unlike a box of chocolates.
  3. Life is a gift.

Lewis Carroll published a book of about a hundred puzzles like this one. Read it online: introduction; puzzles. My nephew IM and I stumbled upon them in Memphis last week. He pretty much knocked them out of the park one at a time.

They're fairly easy to make, if you know some logic and some algebra. Here are a few more (but Lewis Carroll's are the most sublime nonsense—you should probably try those instead.)

Concerning fashion

  1. Anyone lacking impeccable fashion sense might wear a rhinestone sombrero.
  2. Anyone who might wear a rhinestone sombrero can't dance.
  3. All penguins can dance.

Concerning animals

  1. Animals that are active during the day are either featherless or tasty—or both.
  2. No creature is both nocturnal and naturally funny.
  3. Chickens have feathers.
  4. Chickens are naturally funny.

Concerning the inhabitants of this town

  1. All the monsters in this town are carnivores.
  2. A carnivore would eat anything made of meat.
  3. No creature in this town would eat any other creature in this town.
  4. Humans are made of meat.

Concerning monsters

  1. Only monsters can make the ground tremble.
  2. Two-year-olds and raccoons get into everything (two-year-old raccoons doubly so).
  3. If something gets into everything, but it doesn't emit terrifying shrieks, it must be a raccoon.
  4. All firebreathing creatures are monsters.
  5. Opera singers can make the ground tremble.
  6. Raccoons are not human.
  7. A creature that isn't a monster doesn't have slavering fangs.
  8. If a creature emits terrifying shrieks, then either it breathes fire, it has slavering fangs, or it's an opera singer.

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