A barrel of cider weighs 60 pounds. When a certain liquid is added to the barrel, the total weight drops to 40 pounds, yet the barrel remains completely full. What was added?
Holes.
Adding holes to the barrel allows some cider to drain out, reducing the total weight while keeping the remaining space filled with air.
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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