Solution
= Solution
A <partition of a set> $\Omega$ is a collection of nonempty <subsets> $B_i$ such that $B_i\cap B_j=\varnothing$ for $i\ne j$ and $\bigcup_{i\in I}B_i=\Omega$. Thus \b[every outcome lies in exactly one cell]. For a probability-space partition the cells must also be measurable <events>. Nonempty cells may nevertheless have probability zero.