Thursday, May 28, 2009

12 Balls

Wednesday morning, out of sheer impulse I navigated to Willy Wu’s riddles site consisting of the best puzzle compilation on internet (I added the site to the links section as well). The puzzle that was staring at me was the 12 Balls one:

You have 12 identical-looking balls. One of these balls has a different weight from all the others. You also have a two-pan balance for comparing weights. Using the balance in the smallest number of times possible, determine which ball has the unique weight, and also determine whether it is heavier or lighter than the others.

I figured the solution once I was able to find time to put some random thoughts to this puzzle. I’m currently working on creating a visio diagram to display the solution but if you’re not familiar with the puzzle and feel challenged enough to attempt a stab at it without searching online for a solution, feel free.

If after putting some time into it, you’re feeling frustrated and just want the solution, go ahead and google. If you just want some hint(s) and not the complete solution, let me know and I’ll post it before I post the solution.

Wednesday, May 27, 2009