Plinks, Plonks, and Plunks

If all plinks are plonks and some plunks are plinks, which of these statements must be true?

  • All plinks are plunks.
  • Some plonks are plunks.
  • Some plinks are not plunks.

Remark: “Some” means more than 0.

The first statement says that the set of plonks contains the set of plinks, and the second statement says that there is at least one plunk-plink. Therefore, that plunk-plink must also be a plonk, and the second statement is true.

The first and the third statements, however, do not need to be true. Indeed, it is possible that there is a plink that is not a plunk, or that all plinks are plunks.

A Dream Last Night

The director of a company wakes up early for a morning flight. He realizes that he forgot some papers at work and goes there. In the office, he meets the night watchman who is leaving for home. The watchman stops the director and tells him that he shouldn’t fly. “I had a dream last night,” the watchman says, “I saw you crash. I saw you die sir, please do not fly today.”

The director listens to the advice of the watchman and decides not to travel. On the next day, the director returns, gives the watchman a generous bonus, and then he fires him. Why?

The plane indeed crashed, so the watchman saved the director’s live. However, apparently, he has been sleeping during his shift, which is the reason the director fires him.