The profit on the sale of a product is 25%. What will be the loss per cent, if the values of cost price and selling price are interchanged?

Correct option is A

Given:
Profit on the product = 25%.

Formula Used:
If profit percentage is P%, then the loss percentage when CP and SP are interchanged is given by:
Loss% = (P / (100 + P)) × 100
Solution:
Loss% = (25 / (100 + 25)) × 100 = (25 / 125) × 100 = 20%

Alternate Method:

SP = CP + (25% of CP)
Substituting CP = 100:
SP = 100 + (25/100) * 100 = 100 + 25 = 125
Now, after interchanging, the new Cost Price (CP) = 125, and the new Selling Price (SP) = 100.

Loss = New CP - New SP
Loss = 125 - 100 = 25
Loss Percentage = (Loss / New CP) × 100
Loss Percentage = (25 / 125) × 100 = 20%