2022 AMC 12A Problem 3

Below is the professionally curated solution for Problem 3 of the 2022 AMC 12A, from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 2022 AMC 12A solutions, or check the answer key.

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Concepts:areatilingrectangle

Difficulty rating: 1130

3.

Five rectangles, A,A, B,B, C,C, D,D, and E,E, are arranged in a square as shown below. These rectangles have dimensions 1×6,1\times6, 2×4,2\times4, 5×6,5\times6, 2×7,2\times7, and 2×3,2\times3, respectively. (The figure is not drawn to scale.) Which of the five rectangles is the shaded one in the middle?

AA

BB

CC

DD

EE

Solution:

The five areas are 6, 8, 30, 14,6,\ 8,\ 30,\ 14, and 6,6, which sum to 64.64. So the square is 8×8.8\times8.

Placing CC (5×65\times6) across the top left, DD (2×72\times7) up the right side, EE (2×32\times3) in the lower left, and AA (1×61\times6) along the bottom leaves a central 2×42\times4 gap, which is exactly rectangle B.B.

Thus, the correct answer is B.

Problem 3 in Other Years