Ryan was working on some homework the other day, and asked for some help. (He’s in Grade 2.) He was doing some logic puzzles, which I used to love as a kid. The first one was: There are four birds sitting on a fence. Colour each of them according to these rules:
- The blue bird is not last
- The yellow bird is between the green bird and the blue bird
- The red bird is first
“OK, this is easy”, I thought. Yellow is between green and blue, so we have GYB somewhere. Since blue is not last, it must be GYBR. But the last clue says that red is first, so it must be RGYB. But that makes blue last, so that’s wrong too. I must have looked at this for a couple of minutes before telling Ryan that there must have been a typo somewhere, since the puzzle is not solvable. He skipped it and went on to the next one.
Later, I was going to show it to Gail, and make some kind of joke about the fact that they gave Ryan an impossible question to answer, when I noticed that the birds had all been coloured in. I looked at the colours, and smacked myself in the head for being so stupid. Of course the question was not impossible. When it said yellow is between green and blue, I assumed that meant GYB in that order — it actually meant BYG. Putting red first (as clue 3 dictates) gives you RBYG, which fits all the clues. Boy, did I feel like a moron.
I knew there would come a time when I would not be able to help Ryan with his homework. I just figured I had a couple more years….