If the cost price of 19 books is equal to the selling price of 25 books, the percentage loss is:

Correct option is C

Given:

Cost price of 19 books = Selling price of 25 books

Formula Used:

$$\text{Loss Percentage} = \left( \frac{\text{Loss}}{\text{Selling Price}} \right) \times 100$$​

Solution:

Let the cost price of 1 book be ₹1.

Therefore, the cost price of 19 books is ₹19.

Since the cost price of 19 books is equal to the selling price of 25 books, the selling price of 25 books is ₹19.

Selling price of 1 book = $$\frac{₹19 }{ 25}$$​= ₹0.76

Loss per book = Cost price - Selling price = ₹1 - ₹0.76 = ₹0.24

​$$\text{Loss Percentage} = \left( \frac{\text{Loss}}{\text{Selling Price}} \right) \times 100$$​​

Loss percentage = $$\frac{₹0.24} { ₹1}$$​ × 100 = 24%

Therefore, the percentage loss is 24%.

Alternate Method :

Cost Price : Selling Price = 19 : 25

Loss = 25 - 19 = 6 parts

$$\text{Loss Percentage} = \left( \frac{\text{Loss}}{\text{Selling Price}} \right) \times 100$$​​

Loss percentage = $$\frac{6}{25}$$​ × 100 = 24%

Therefore, the percentage loss is 24%.