Problem #21 MEDIUM
Glasses in the Dark
Meta Google Logic
Problem Statement
You are blindfolded and seated at a round turntable with four identical glasses arranged at the four compass positions. Each glass is either upright (opening facing up) or inverted (opening facing down) in some hidden starting configuration. Each round: you may pick any one or two glasses and flip them however you like, then you must step back. An assistant then silently rotates the turntable by a random unknown number of positions. You win the moment all four glasses face the same direction. Can you guarantee a win? If so, what is your strategy?
Answer & Quick Explanation
Logged-in Users Only
You must be logged in to view the answer and check your solution. Signing up is free and takes less than a minute.
Detailed Editorial Solution
Detailed Editorial Solution is Premium
Unlock detailed step-by-step mathematical proofs, logic explanations, and company-specific interview preparation pathways.