Two cards are drawn at random from a standard pack of 52 playing cards without replacement. What is the probability that both drawn cards are aces?

Difficulty: Medium

Correct Answer: 1/221

Explanation:


Introduction / Context:
Card-draw probabilities often use combinations since order does not matter for the set of drawn cards. There are 4 aces in a 52-card deck; we want both drawn cards to be aces without replacement.


Given Data / Assumptions:

  • Deck size = 52, aces = 4.
  • Draw 2 cards without replacement.


Concept / Approach:

  • Total unordered draws = C(52,2).
  • Favorable draws (both aces) = C(4,2).
  • Probability = C(4,2)/C(52,2).


Step-by-Step Solution:

C(4,2) = 6C(52,2) = 52*51/2 = 1326Probability = 6/1326 = 1/221


Verification / Alternative check:
Sequential method: P(first ace) = 4/52; P(second ace | first ace) = 3/51; product = (4/52)*(3/51) = 12/2652 = 1/221. Same result.


Why Other Options Are Wrong:

  • 2/13 and 2/26 ignore shrinking deck or use wrong counting.
  • “None of these” is false because 1/221 is exact.


Common Pitfalls:

  • Using replacement probabilities or confusing ordered vs unordered counting.


Final Answer:
1/221

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