In a class of 25 distinct students, how many different 3-student committees can be formed? (Order of students within the committee does not matter.)

Difficulty: Easy

Correct Answer: 2300

Explanation:

Introduction / Context:Forming committees is choosing subsets, not arranging sequences. The correct tool is combinations C(n, k).

Given Data / Assumptions:

  • n = 25 students.
  • k = 3 students per committee.

Concept / Approach:Compute C(25, 3) = 25! / (3! * 22!).

Step-by-Step Solution:

C(25, 3) = (252423) / (321) = (60023)/6 = 2300.

Verification / Alternative check:Multiplying 2524*23 = 13,800 and dividing by 6 gives 2300 exactly.

Why Other Options Are Wrong:Nearby values (2200, 2400, 3200) reflect arithmetic slips or using permutations.

Common Pitfalls:Confusing ordered selections with unordered committee formation.

Final Answer:2300

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