Cracking Master Locks

As I was planning my trip to the hostels in Europe, I found that I need to have a combination lock to put on my locker. So, I dug out my Master Locks from high school, but the combinations for most of them were only written in one place and were stolen a few years ago. This left me with 4 locks without a combination.

Since I had nothing better to do, I thought I'd figure out the combinations and Kevin decided to help me too. At first, this sounded like a daunting task, as there appear to be 40^3 = 64,000 possible combinations. But, it turns out that there are only actually only 64 possible combinations for the first 2 numbers if you know the last number. And, with practice it gets easy to figure out the last number in about 1 minute. (That's true. We only guessed the last number incorrectly twice over the entire 4 locks.)

After cracking the combination for the first 3 locks, I had enough practice that the 4th lock took under 20 minutes to figure out. How is that possible? Well, the internet helps. Those links show how to break Master Lock combinations, but they claim that it also works on other manufacturers' locks as well.

You learn something new every day.