Problem number 11. Kanga wants to reach the koala without going through any of the colored squares. Which route can she take? A, B, C, D, or E? We could solve this problem by tracing each of the paths and seeing which one works. But I would like to try to do it a little bit more quickly by seeing which of the paths definitely will not work. If you look at our choices, the first four arrows in each of the paths are the same. Right, right, up, up. So if we trace those, right, right, up, up, Kanga is on this square. Now several of these choices then show her going up, which would bring her into the water. That's choice C and choice E. So we can eliminate those two choices as valid paths. The other three paths all have her go to the right two times. From here, we see that she could go to the right or up and still be okay. But notice that in choice B, she would keep going to the right several more times, ending up in the water. So choice B does not work. And the other two choices, she goes up two times. So she was here, up, up, and then she just needs to go to the right. Well, that's shown in choice A. Right, right, right, and that gets her to the koala. In choice D, she would go the opposite direction, ending up in the colored square or the water. So choice A is the only path that works. The answer is A.

Kanga

koala

pathfinding

colored squares

solution