Final answer:
To achieve an overall gain of 25%, the wholesaler should sell the remaining sacks of rice at a gain percentage of approximately 23.15%. However, this percentage does not match any of the options provided, indicating there may be an error.
Step-by-step explanation:
To determine the gain percent at which the wholesaler should sell the remaining sacks of rice to obtain a total gain of 25%, we first need to calculate the total cost price of the 20 sacks and the total desired selling price to achieve a 25% profit. Then we can calculate the selling price of the 8 sacks and the required profit percentage on the remaining 12 sacks.
The cost price of 20 sacks is Rs. 36,000. Therefore, to achieve a 25% gain on the entire transaction, the total selling price must be:
Rs. 36,000 + (25/100) × Rs. 36,000 = Rs. 36,000 + Rs. 9,000 = Rs. 45,000
He sold 8 sacks at a 10% profit, so the selling price of these 8 sacks would be:
(10/100) × (Rs. 36,000/20) × 8 + (Rs. 36,000/20) × 8 = Rs. 18,400
Now the remaining amount to achieve Rs. 45,000 total selling price is:
Rs. 45,000 - Rs. 18,400 = Rs. 26,600
The cost price of the remaining 12 sacks is (Rs. 36,000/20) × 12 = Rs. 21,600. The required gain percentage is then:
((Rs. 26,600 - Rs. 21,600) / Rs. 21,600) × 100 = (Rs. 5,000 / Rs. 21,600) × 100 = 23.15%
This gain percentage does not match any of the options provided, suggesting a possible error in the question or the options. The closest option to 23.15% is 25%, but it's not listed in the answer choices provided.