Final answer:
The cost price of the watch is Rs 1920 and the profit percentage for Rs 2040 is 6.25%.
Step-by-step explanation:
To find the cost price of the watch, we can use the formula:
Cost Price = Selling Price / (1 + Profit Percentage)
Given that the selling price is Rs 2400 and the profit is 25%, the cost price can be calculated as:
Cost Price = 2400 / (1 + 0.25) = Rs 1920
To find the profit percentage for Rs 2040, we can use the formula:
Profit Percentage = (Selling Price - Cost Price) / Cost Price
Given that the selling price is Rs 2040 and the cost price is Rs 1920, the profit percentage can be calculated as:
Profit Percentage = (2040 - 1920) / 1920 = 0.0625 = 6.25%