Answer: Number of ways to select r items from n (order does not matter).
- A Number of distinct ordered arrangements possible for r items chosen from n
- B Number of ways to select r items from n (order does not matter)
- C n raised to the power r, representing repeated outcomes with replacement
- D The numeric difference n minus r, treated loosely as a selection count
Correct answer: B. Number of ways to select r items from n (order does not matter)
Explanation: nCr = n!/[r!(n-r)!] counts unordered selections (combinations).
Counting tree for selecting 2 items from {A, B, C} without repetition: 3 x 2 = 6 ordered arrangements.
Concept context
Counting, arrangements, and selections