2001 AMC 12 Problem 10
Attempt Problem 10 of the 2001 AMC 12 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 2001 AMC 12 solutions, or check the answer key.
All problems are used with official legal permission of the Mathematical Association of America (MAA).
10.
The plane is tiled by congruent squares and congruent pentagons as indicated. The percent of the plane that is enclosed by the pentagons is closest to
Answer: D
Solution:
The pattern repeats over a block of nine unit squares. Four of these nine squares are not covered by pentagons; the rest of the area belongs to the pentagons.
So the pentagons enclose which is closest to
Thus, the correct answer is D.
Problem 10 in Other Years
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