A few days ago, I stumbled upon a fun little riddle which you can see here. (The answer is here but try to solve it first). When I was a kid, I used to do brain teasers, tests, and puzzles all the time, and I was pretty good at them. I stopped being a student decades ago, though, and even though this riddle was labeled “Easy”, I gave up.

The approach I took was a logical and binary one. I simply tried the direct approach of trying to figure out which switches corresponded to which light. When I found the problem unsolvable and peeked at the answer, I saw that I had totally missed another data point (I won’t allude to it here, since I don’t want to spoil the puzzle for you). (more…)