Answer: Number of arrangements of r from n distinct objects.
- A Number of unordered selections of r items from n
- B Number of arrangements of r from n distinct objects
- C The product of n and r counted as a count
- D Sum of n and r treated as a combination count
Correct answer: B. Number of arrangements of r from n distinct objects
Explanation: nPr = n!/(n-r)! counts ordered arrangements (permutations) of r items from n distinct items.
Counting tree for selecting 2 items from {A, B, C} without repetition: 3 x 2 = 6 ordered arrangements.
Concept context
Counting, arrangements, and selections