This sheet presents the Mathematics mock examination from the North-West Regional Branch for the BEPC 2021 session in Cameroon, accompanied by its detailed answer key. Regional mock examinations are valuable training tools, as they are designed by experienced teachers and faithfully reflect the format and difficulty level of the official examination.

The exam is structured into two main parts. Part A focuses on resource evaluation and is divided into numerical activities and geometric activities. The numerical activities comprise three exercises. The first requires calculating fractional expressions and reducing them to irreducible fractions, as well as simplifying expressions containing radicals (square roots) and performing bounding calculations. The second exercise covers expansion, reduction, and factorization of algebraic expressions, along with the study of rational fractions (conditions of existence, simplification). The third exercise presents a concrete problem involving weighted average calculation with different coefficients.

The geometric activities include two exercises. The first works within an orthonormal coordinate system and requires plotting points, proving vector orthogonality, calculating distances and the tangent of an angle, then determining a Cartesian equation of a line. The second exercise focuses on circle geometry: inscribed angles, central angles, and the relationships between angles intercepting the same arc.

Part B assesses competencies through a contextualized life situation featuring Mrs. ABROU, a yogurt maker. Her oven is shaped like a truncated cone of revolution with a total volume of 50,868 cm³. Students must calculate volumes, determine the number of sachets that can be filled, and solve an economic profitability problem incorporating production costs and profit margins.

The skills mobilized cover numerical calculation (fractions, radicals), algebra (factorization, equations), analytical geometry (coordinate systems, vectors, line equations), circle geometry, and spatial geometry (volumes of solids of revolution). The complete answer key guides students through each resolution step, making this sheet indispensable for methodical BEPC mathematics preparation.