Every inhabitant of a certain distant planet has one of three possible occupa- tions: educator, lawyer, or politician. The educators always tell the truth, the politicians always lie, and the lawyers sometimes say the truth and sometimes lie—whatever they happen to feel like. Educators are considered to be members of the upper class, lawyers are members of the middle class, and politicians belong to the lower class. (a) A and B, who live on this planet, say the following: A says: “B is in a higher class than I am.” B says: “That’s not true.” Can we determine the occupations of A and B? (b) One day we meet three inhabitants of the planet: C, D, and E. We know that all three have different occupations. They tell us the following: C says: “I am a lawyer.” D says: “That’s true.” E says: “I am not a lawyer.” Can we determine the occupations of these three people?
Every inhabitant of a certain distant planet has one of three possible occupa-
tions: educator, lawyer, or politician. The educators always tell the truth, the
politicians always lie, and the lawyers sometimes say the truth and sometimes
lie—whatever they happen to feel like. Educators are considered to be members
of the upper class, lawyers are members of the middle class, and politicians
belong to the lower class.
(a) A and B, who live on this planet, say the following:
A says: “B is in a higher class than I am.”
B says: “That’s not true.”
Can we determine the occupations of A and B?
(b) One day we meet three inhabitants of the planet: C, D, and E. We know
that all three have different occupations. They tell us the following:
C says: “I am a lawyer.”
D says: “That’s true.”
E says: “I am not a lawyer.”
Can we determine the occupations of these three people?
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