2 months ago
I left 7 puzzles about series for 10 yo to solve last night. This morning he reported he'd only solved 5. But one was insoluble because I skipped a number, and one I forgot the rule I used to generate and can't solve myself. So he was happy to hear he can solve as many as me.
I'm now going to expend some serious effort on the one I can no longer solve. What a strange problem, to have created a puzzle that one can't solve. Though come to think of it, that's the experience of many a programmer returning to their own code.
Hah, solved it. Phew!