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.
SOLUTION
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.
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