Explanation:

- The article is initially priced at Rs15,000.

- A discount of 12% is applied to the listed price.

- The new price after the first discount: Rs15,000 - (12% of Rs15,000) = Rs15,000 - Rs1,800 = Rs13,200.

- The goal is to bring the net selling price down to Rs12,078.

- We need to calculate the additional discount on Rs13,200.

$$

\text{Discount needed} = \left(1 - \frac{12,078}{13,200}\right) \times 100

$$

$$

= \left(1 - 0.914545\right) \times 100

$$

$$

= 8.55\%

$$

- Checking the options:

- Option 1: 7.5%

- Option 2: 8.5%

- Option 3: 9%

- Option 4: 8%

- Correct Answer: Option 2 (8.5%)