Answer: 90.
- A 90
- B 720
- C 180
- D 360
Correct answer: A. 90
Explanation: 6 letters with A repeated 2×, B repeated 2×, C repeated 2×. Multinomial: 6!/(2!×2!×2!) = 720/8 = 90. Each of 90 arrangements is distinct.
Counting tree for selecting 2 items from {A, B, C} without repetition: 3 x 2 = 6 ordered arrangements.
Concept context
Counting, arrangements, and selections