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Question

A cubical wooden block of length 10 cm is sliced to produce a cross-section of maximum area. What is the area of the cross-section?

This question was previously asked in
CDS 2 2026 Maths Question Paper (13-Sep-2026)
The correct answer is

\(100\sqrt{2}\ \text{cm}^2\)

For a cube of edge 10 cm, the cross-section of maximum area is the rectangle obtained by slicing along the diagonal plane through a pair of opposite edges. Its sides are the edge (10 cm) and the face diagonal \(10\sqrt{2}\) cm, which is larger than any face or the central hexagonal section. So the maximum cross-sectional area \(=10\times10\sqrt{2}=100\sqrt{2}\ \text{cm}^2\).

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