The selling price of 24 books is equal to the cost price of 30 books. Find the loss or gain percentage.

Correct option is A

Given:

Selling price of 24 books = Cost price of 30 books;

Required: Gain or loss percentage.

Formula Used:

Profit % = $$\left( \frac{SP - CP}{CP} \right) \times 100$$​​

Solution: 

From the condition;

24 SP = 30 CP 

​$$\frac{SP}{CP} = \frac{30}{24} = \frac{5}{4}$$ 

Let SP = 5 and CP = 4 

Profit % = $$\left( \frac{5 - 4}{4} \right) \times 100$$​​

​$$= \frac{1}{4} \times 100 = 25\%$$​​