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UKMT Junior Mathematical Challenge, 2022

Geometry Difficulty 2.0 Junior Find the answer United Kingdom

The diagram shows five squares whose side-lengths, in cm, are 1, 2, 3, 4 and 5. What percentage of the area of the outer square is shaded?

(A) $25\%$ (B) $30\%$ (C) $36\%$ (D) $40\%$ (E) $42\%$

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