A student scored the following marks in 11 questions of a question paper :

3, 4, 7, 2, 5, 6, 1, 8, 2, 5, 7.

Find the median marks.

On arranging the marks in ascending order, we get

1, 2, 2, 3, 4, 5, 5, 6, 7, 7, 8.

Here, n (no. of observations) = 11, which is odd.

$\therefore \text{Median} = \dfrac{n + 1}{2} \text{th observation} \\[1em] = \dfrac{11 + 1}{2} \\[1em] = \dfrac{12}{2} \\[1em] = 6 \text{th observation}$

6th observation = 5.

Hence, the median marks are 5.