Science Fiction Puzzle Tales

By a mathematician famous for his "games" published regularly in "Scientific American", a series of 34 problems in the form of short science fiction stories published from 1976 in "Isaac Asimov's science fiction magazine". The interesting part of these problems comes is that each is extended by a series of three answers, graded by comprehension. It is obvious that the first two do not bring the solution but can lead to it. Pleasant and instructive.