Stage 32 · Counting, Permutations, Combinations & the Binomial Theorem
32.3.5 Combinations with Restrictions
32.3 Combinations: Only Who Was Chosen, Not the Order
Point 5 of 6
32.3.5 Combinations with Restrictions
Core idea'Must include this person', 'at most this many': solve it either by sorting into cases directly or by 'total minus the ones that don't qualify'
Module goal. Tell combinations apart from permutations, master the combination formula and its two key properties, and solve combinations with restrictions plus simple distribution problems