Explanation:

- We have two types of rice being mixed.

- One rice costs Rs 45/kg.

- Rice is mixed in a ratio of 3:2.

- The final mixture is worth Rs 50/kg.

- We need to find the cost of the second rice quality.

Solution:

- Let the cost of the second quality rice be Rs x/kg.

- Using the equation for the weighted average:

$$

\left( \frac{3 \times 45 + 2 \times x}{3 + 2} \right) = 50

$$

- Simplifying, we get:

$$

\frac{135 + 2x}{5} = 50

$$

- Solving:

$$

135 + 2x = 250

$$

$$

2x = 115 \Rightarrow x = 57.5

$$

- Correct option: Option 2, Rs 57.5

.