A teacher places three shapes on the board: a red circle, a blue square, and a green triangle. She gives three clues about her secret shape: 1. It has straight sides. 2. It is not red. 3. It does not have three sides. Which shape did she select?
The blue square
Clue 1 eliminates the red circle. Clue 2 eliminates red items (circle already out). Clue 3 eliminates the green triangle (which has three sides). The remaining shape is the blue square.
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: Medium. More like this: Logic riddles with answers or try Einstein's Logic Grid for a different kind of puzzle.
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