2004 AMC 10A Problem 13

Attempt Problem 13 of the 2004 AMC 10A below, then check your answer against the professionally curated solution from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 2004 AMC 10A solutions, or check the answer key.

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13.

At a party, each man danced with exactly three women and each woman danced with exactly two men. Twelve men attended the party. How many women attended the party?

88

1212

1616

1818

2424

Answer: D
Concepts:double countingcounting pairs
Difficulty rating: 1190
Solution:

The number of dancing pairs is 123=36,12 \cdot 3 = 36, counting from the men's side. Each woman was in exactly 22 pairs, so the number of women is 362=18. \dfrac{36}{2} = 18.

Thus, the correct answer is D.

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