2017 AMC 10A Problem 3

Below is the professionally curated solution for Problem 3 of the 2017 AMC 10A, from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 2017 AMC 10A solutions, or check the answer key.

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Concepts:area decompositionrectangle

Difficulty rating: 960

3.

Tamara has three rows of two 66-feet by 22-feet flower beds in her garden. The beds are separated and also surrounded by 11-foot-wide walkways, as shown on the diagram. What is the total area of the walkways, in square feet?

7272

7878

9090

120120

150150

Solution:

We can see that the width of the garden is 26+31=15.2 \cdot 6 + 3 \cdot 1 = 15. We can also see that the height is 32+41=10. 3 \cdot 2 + 4 \cdot 1 = 10. The total area of the garden is therefore 1510=150.15 \cdot 10 = 150. The area of all the flower beds is 626=72. 6 \cdot 2 \cdot 6 = 72. Subtracting this from the area of the garden yields 15072=78,150 - 72 = 78, which is the area of the walkways.

Thus, B is the correct answer.

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