Measuring PuzzlesStarter PuzzlesPuzzle GamesLogic PuzzlesJigsaw PuzzlesNumber PuzzlesCard PuzzlesEinstein PuzzlesSam Loyd PuzzlesAlgebra Puzzles
Three Boxes with Two Balls Each Puzzle - Solution
The Puzzle:
The first box has two red balls. The second box has two blue balls. The third box has a red and a blue ball.
Boxes are labeled but all labels are wrong!
You are allowed to open one box, pick one ball at random, see its color and put it back into the box, without seeing the color of the other ball.
How many such operations are necessary to correctly label the boxes?
Our Solution:
Just One!
Because we know all labels are wrong.
So the Red-Blue box must be either Red-Red or Blue-Blue. Selecting one ball from Red-Blue will let you know which.
And the other two boxes can then be worked out logically.