Insight · ★★★☆☆ · ~6 min
Fruit Magic (Invariant Proof)
Combine fruit by rules — can you always end with one fruit? An invariant says otherwise.
by MindYourPuzzle
A hat contains 13 apples, 15 bananas, 17 cherries. When two different fruits collide, both transform into the third type (e.g., 1 apple + 1 banana → 2 cherries).
Can any sequence of collisions result in all 45 fruits being the same type?
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