Answer: 10.
- A 10
- B 20
- C 15
- D 5
Correct answer: A. 10
Explanation: 5C2 = 5!/(2! × 3!) = (5×4)/(2×1) = 10.
Counting tree for selecting 2 items from {A, B, C} without repetition: 3 x 2 = 6 ordered arrangements.
Concept context
Counting, arrangements, and selections