Answer: 20.
- A 10
- B 20
- C 15
- D 25
Correct answer: B. 20
Explanation: 5P2 = 5!/(5-2)! = 5!/3! = 5×4 = 20.
Counting tree for selecting 2 items from {A, B, C} without repetition: 3 x 2 = 6 ordered arrangements.
Concept context
Counting, arrangements, and selections