WAEC Mathematics 2021 Paper

Concept:In a pie chart, the angle of each sector is proportional to its quantity. The total angle is $360^\circ$.Explanation:Let the unknown angle for oranges be $M$.The known angles from the chart are $100^\circ$, $60^\circ$, and $80^\circ$.So:$$100 + 60 + 80 + M = 360$$$$M = 360 - 240 = 120$$Therefore, the orange sector is $120^\circ$, and the apple sector is $80^\circ$.Let the total number of fruits be $F$.Since there are 60 apples:$$\frac{80}{360}F = 60$$$$F = \frac{60 \times 360}{80} = 270$$So total fruits is $270$.Number of oranges:$$\frac{120}{360} \times 270 = 90$$Answer:90 oranges.