Solution: The robot takes 8 steps, each independently choosing to go right (increase $x$) or up (increase $y$), uniformly at random (assume fair walk). The endpoint is $(x, 8 - x)$ for $x = 0,1,\dots,8$, so $x$ follows a binomial distribution: $x \sim \text{Binomial}(8, \frac{1}{2})$.

Tue, 05 May 2026 19:20:22 +0000

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