You are presented with three jars labeled 'Red Marbles', 'Blue Marbles', and 'Mixed Marbles'. Every single jar is labeled incorrectly. You may draw just one marble from one jar without looking inside. Which jar should you sample from to determine the correct label for all three jars?
The jar labeled 'Mixed Marbles'
Since all labels are wrong, the 'Mixed' jar must contain only Red or only Blue. If you pull a Red marble from it, that jar is pure Red. The jar labeled 'Blue' cannot be Blue (all labels wrong) or Red (already found), so it must be Mixed. The jar labeled 'Red' must then be Blue.
About this riddle
Logic riddles give you a few facts and ask what must be true. List what you know, cross out what cannot be, and see what is left.
Difficulty: Hard. More like this: Logic riddles with answers or try Einstein's Logic Grid for a different kind of puzzle.
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