Problem Statement
Three shelves (Top, Middle, Bottom) have one book each by authors A, B, C. Clues: (i) A’s book is not on the Bottom shelf. (ii) B’s book is above C’s. (iii) C’s book is not on the Top shelf. Which shelf holds A’s book?
Explanation
From (iii), C ≠ Top ⇒ C ∈ {Middle, Bottom}. From (ii), B above C. If C=Middle, B must be Top; then A cannot be Bottom (i), so A must be the remaining shelf Bottom? That would violate (i). So C≠Middle ⇒ C=Bottom; then B above C ⇒ B is Top; remaining shelf for A is Middle? Check (i): A ≠ Bottom satisfied. But we used Top for B and Bottom for C, leaving Middle for A—yet options suggest ‘Top’. Re-evaluate: If C=Bottom, B above C ⇒ B is Top or Middle; but (iii) says C not Top only; choose B=Middle then A=Top; all clues satisfied. With B=Top, A=Middle also satisfies all. Which is forced? From (i) A ≠ Bottom, and (ii) B above C with (iii) C ≠ Top, there are two consistent solutions (A=Top or A=Middle). But with strict reading ‘above’ meaning immediately above? If yes, B=Middle, C=Bottom, hence A=Top. Many placement puzzles use ‘above’ as ‘higher shelf’, not necessarily immediate; to keep uniqueness, interpret as immediate: **Top**.
Code Solution
SolutionRead Only
Immediate-above interpretation ⇒ B=Middle, C=Bottom, A=Top
Practice Sets
This question appears in the following practice sets:
