Consider the following distribution :

Class	Frequency
0 - 5	10
5 - 10	15
10 - 15	12
15 - 20	20
20 - 25	9

The sum of lower limits of the median class and the modal class is :

1. 15

2. 25

3. 30

4. 35

We construct the cumulative frequency distribution table as under :

Here n (total no. of observations) = 66.

As n is even,

By formula,

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

$= \dfrac{\dfrac{66}{2} \text{th observation} + \Big(\dfrac{66}{2} + 1\Big) \text{th observation}}{2} \\[1em] = \dfrac{33 \text{th observation} + \Big(33 + 1\Big) \text{th observation}}{2} \\[1em] = \dfrac{33 \text{th observation} + 34 \text{th observation}}{2}$

As observation from 26th to 37th lie in the class 10 - 15,

∴ Median class = 10 - 15.

Since the class 15 - 20 has highest frequency i.e. 20.

∴ Modal class = 15 - 20.

Sum of lower limit of median and modal class = 10 + 15 = 25.

Hence, Option 2 is the correct option.