Content atlas · skill

Count permutations and combinations with constraints

The learner can count permutations and combinations with constraints. This capability is distinct from mere exposure to or isolated use of factorials; counting principle.

2 published problems

1. Shedletsky’s Self-Checking Formula Cabinet — Open a cabinet of sixteen formulas, discover how it checks itself, and repair one damaged notation pair.
2. The Empty Arrangement — Inspect three Gallery plates as the display shrinks from two seals to none, then follow the empty arrangement through factorials and identity permutations.