The median of the following data is:

x	f
10	2
20	3
30	2
40	3
50	1

1. 30

2. 31

3. 35

4. 40

Cumulative frequency distribution table is:

Here, n = 11, which is odd.

By formula,

Median = $\dfrac{\text{n} + 1}{2} \text{ th observation}$

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

From table,

6th observation corresponds to 30.

∴ Median = 30

Hence, Option 1 is the correct option.