2001 AMC 10 Problem 5
Attempt Problem 5 of the 2001 AMC 10 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 10 solutions, or check the answer key.
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5.
How many of the twelve pentominoes pictured below have at least one line of symmetry?
Answer: D
Solution:
Checking each pentomino for a reflection line, exactly six have at least one: the straight bar, the plus, the T-shape, the U-shape, the V-shape, and the W-shape. The remaining six have no line of symmetry.
Thus, the correct answer is D.
Problem 5 in Other Years
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