WAEC 2021 · Paper 1 · Q35

Find the first quartile of 7, 8, 7, 9, 11, 8, 7, 9, 6 and 8.

Worked solution (try it first)

Put the 10 numbers in order: 6, 7, 7, 7, 8, 8, 8, 9, 9, 11.
$Q_1$ is at position $\frac{10}{4} = 2.5$ , halfway between the 2nd and 3rd values.
Both are 7, so $Q_1 = 7.0$ , option B.