WAEC Mathematics 2013 Paper

Concept:The angle of a sector in a pie chart is proportional to its quantity.Explanation:Total angle in a pie chart is $360^\circ$.Angles for Arts, Business, and Science are:Arts $= 90^\circ$, Business $= 75^\circ$, Science $= 45^\circ$.Sum of these three angles $= 90^\circ + 75^\circ + 45^\circ = 210^\circ$.Therefore, angle for Technical class $= 360^\circ - 210^\circ = 150^\circ$.Number of textbooks for Technical class $= \dfrac{150^\circ}{360^\circ} \times 600$.$= \dfrac{5}{12} \times 600 = 250$.Answer:The Technical class has $250$ textbooks.Therefore, the correct option is D. 250.