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MathNet 2022-part-06 — 196 problems (EN–VI) Question 142

Math Olympiad Vault · MathNet 2022-part-06 — 196 problems (EN–VI)

Question 142

In three-dimensional space, let $S$ be the region of points $(x, y, z)$ satisfying $-1 \leq z \leq 1$. Let $S_{1}, S_{2}, \ldots, S_{2022}$ be 2022 independent random rotations of $S$ about the origin $(0,0,0)$. The expected volume of the region $S_{1} \cap S_{2} \cap \cdots \cap S_{2022}$ can be expressed as $\frac{a \pi}{b}$, for relatively prime positive integers $a$ and $b$. Compute $100a + b$.