$n$ points are chosen randomly and independently on a circle, each with the uniform distribution. What is the probability that all $n$ points are contained in some closed semicircle? We received only one solution, from Prof. Vladislav Kargin. His solution is the same as our "in-house" solution. The probability in question is $\frac{n}{2^{n-1}}$. For a justification and more details see the following link {{:pow:2022sproblem6.pdf|Solution}}.