The Three Locks Puzzle | Logic Game 

Question :

You have three locks and three keys, each key corresponding to one lock. Unfortunately, all the keys are mislabeled. Your task is to determine which key unlocks which lock, but you're only allowed to test the keys by trying them in the locks.

Here are the clues to help you solve the puzzle:

One key fits one lock perfectly.

One key fits no lock at all.

One key fits two locks, but only one of them correctly.

Can you figure out which key unlocks which lock?

Take your time to think about it, and comment your answer when you're ready!

Solution:

Label the keys and locks: Let's label the keys A, B, and C, and the locks X, Y, and Z.

Test key A: Since one key fits one lock perfectly, test key A in lock X. If it doesn't fit, move to the next lock.

Test key B: Now test key B in lock X. If it fits, mark it down. If it doesn't, it must fit lock Y or Z.

Test key C: Since one key fits no lock at all, test key C in lock X. If it doesn't fit, mark it down. If it does fit, it must be the key that fits two locks.

Test key C in lock Y: If key C fits lock Y, then key A must fit lock Z, and key B must fit lock X.

Test key C in lock Z: If key C fits lock Z, then key A must fit lock Y, and key B must fit lock X.

Now, you've tested all combinations. One key fits perfectly, one key fits no lock, and one key fits two locks but only one correctly.

So, the solution is:

Key A fits lock Y.

Key B fits lock X.

Key C fits locks Z and X (but only fits lock X correctly).