Explanation:

- Discounted Price & Original Selling Price: The washing machine's value after a 15% discount is Rs 29,750.

- Calculation of Original Price: The original selling price can be calculated as $\frac{29,750}{0.85}=35,000$.

- Selling Price & Profit: Without discount, the machine's selling price is Rs 35,000 with a 12% gain.

- Cost Price Calculation: Using the formula: $\text{Cost Price}=\frac{\text{Selling Price}}{1+\text{Profit Percentage}}$, we substitute: $\text{Cost Price}=\frac{35,000}{1.12}=31,250$.

- Option 1: Rs 31,250

- Option 2: Rs 31,500

- Option 3: Rs 31,750

- Option 4: Rs 32,000

- Correct Answer: Option 1 - Rs 31,250