Author note — to cover (Higher)

Higher only, N5's braced clause. Multiplying choice counts across independent stages: codes, menus, outfits; arrangements without repetition where choices shrink slot by slot; restrictions like a fixed first digit. Factorial and nCr notation are A level; Foundation counts by exhaustive listing on systematic-listing. (N5)

• Fluency — multiplying choices across independent slots: menus, codes and outfits (4 questions).
• Application — arrangements and selections without repetition, the factor shrinking slot by slot (4 questions).
• Catch — repeats-forbidden against repeats-allowed on near-identical prompts, where the memorised formula picks the wrong count (4 questions).