Answer: 6P2 × 4C1.
- A 6P2 × 4
- B 6C3 × 2
- C 6P2 × 4C1
- D 6 × 5 × 4
Correct answer: C. 6P2 × 4C1
Explanation: Step 1: arrange first 2 from 6 in order → 6P2 = 6×5 = 30. Step 2: pick the 3rd from remaining 4 (unordered) → 4C1 = 4. Total = 30×4 = 120 = 6P2×4C1.
Counting tree for selecting 2 items from {A, B, C} without repetition: 3 x 2 = 6 ordered arrangements.
Concept context
Counting, arrangements, and selections