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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