Padma purchased 80 kg of tomatoes for ₹320 and sold them at the rate of ₹4.50 per kg. Find the percentage of her gain.

Correct option is A

Given:
Cost Price (CP):

Total cost for 80 kg of tomatoes = ₹320

Selling Price (SP):

Selling rate per kg = ₹4.50

Total selling price for 80 kg = ₹4.50 × 80 = ₹360

Formula Used:
​$$\text{Profit} = \text{Selling Price (SP)} - \text{Cost Price (CP)}$$​
​$$\text{Profit Percentage} = \left( \frac{\text{Profit}}{\text{Cost Price}} \right) \times 100$$​
Solution:
​$$\text{Profit} = \text{SP} - \text{CP} = 360 - 320 = ₹40$$​
​$$\text{Profit Percentage} = \left( \frac{40}{320} \right) \times 100 = 12\frac{1}{2}\%$$

Option (A) is right.