Intellectual quiz.

Of course, participation is not mandatory. If you want to participate, you do; if you don't, you don't. If you don't know how to solve something, just don't write anything. I was just thinking... For the tasks that will be part of a competition, you'll probably need to send them to me via private message... I mean, the solutions to the tasks. So that no one copies from anyone else. I'll post the solutions that are closest to the correct answer and the most interesting ones here, in this thread. If the thread becomes popular, I might even keep statistics. Math competition problems require a certain base of knowledge in the subject to solve them, but they also require a lot of ingenuity. But don't be discouraged if you're not good at math. I have some simpler problems (seemingly starting from the 5th grade), so you can solve those. If the problems for older grades are too difficult, I won't post them anymore. I think I'll start with a mini-quiz on some not-so-difficult math competition problems, then we can solve "Kangaroo" problems together, and then we'll see. We'll need to take a break from math, I think. In principle, if you want, I can post a couple of problems right now...