BECE Mathematics 2025 Paper

Concept:When every length is enlarged by a scale factor $k$, the area is multiplied by $k^2$.Solution:Scale factor $k = 3$, so area factor $= 3^2 = 9$.New area $= 15 \times 9 = 135 \text{ cm}^2$.Key point: Multiplying the area by 3 (giving $45 \text{ cm}^2$) is the trap: both length and width are tripled.Answer:Option D ($135 \text{ cm}^2$)