Solution: The problem requires partitioning 6 distinguishable initiatives into 3 non-empty indistinct subsets. This is given by the Stirling numbers of the second kind, $ S(6, 3) $. The formula for $ S(n, k) $ is $ \frac1k! \sum_i=0^k (-1)^k-i \binomki i^n} $. Plugging in $ n=6 $ and $ k=3 $: - Nelissen Grade advocaten