Correct Answer - Option 1 : 20% loss
Given:
The cost price of 20 books = Selling price of 25 books
Concept:
Gain: The amount gained by selling a product with more than its cost price.
Loss: The amount by which cost price is more than selling price.
Formula Used:
Loss = Cost price – Selling Price
Loss percentage = (Loss/Cost Price) × 100
Calculation:
Let the Selling price of one book be 10 x
So, the selling price of 25 books = 250x
Cost price of 20 books = 250x
⇒ Cost price of 1 book = 250x/20 = 12.5x
Loss = 12.5x - 10x = 2.5x
Loss % = (2.5x/12.5x) × 100 = 2500/125 = 20%
∴ The loss percent is 20%.