WAEC Mathematics 2017 Paper

Concept:The first quartile $Q_1$ is the mark below which $25\%$ of the pupils lie.Explanation:Total frequency, $N = 7 + 4 + 18 + 12 + 8 + 11 = 60$.For the first quartile, find the position $\frac{N}{4} = \frac{60}{4} = 15$.This means the $15$th value in the ordered distribution is needed.Cumulative frequency: mark $0$ has $7$ pupils, marks $0$ and $1$ together have $7 + 4 = 11$ pupils.Marks $0, 1$ and $2$ together have $11 + 18 = 29$ pupils.So the $15$th value lies in the class with mark $2$.Therefore, $Q_1 = 2$.Answer:C. $2.0$