There are 4 keys and 4 locks.
What is the maximum number of times you need to try the locks so as to match all 4 keys to their locks?
Explain.
Solution to the Problem:
The answer is six tries.If you try 3 keys on the 1st lock, you will know that the 4th key is a match.
So, you only need a maximum of 3 tries.
Similarly, the 2nd lock needs a maximum of 2 tries and the 3rd lock needs only 1 try.
Thus, 3 + 2 + 1 = 6 tries are needed.
Correctly solved by:
| 1. Martin Round | Studley, Warwickshire, United Kingdom |
| 2. James Alarie | Flint, Michigan |
| 3. Mr. Paul Carignan's class | Naples, Maine |
| 4. Vasilios Loutrianakis | Park Ridge,Illinois |
| 5. Jonathan Spychalski | Park Ridge,Illinois |
| 6. Amy Sorensen |
Giddings High School, Giddings, Texas |
| 7. Miko Zhang |
Delta High School, Delta, Colorado |