The marked price of a book is 2,400. A bookseller gives a discount of 15% on it. What will be the cost price (in) of the book if he still earns a 20% profit?

Correct option is C

Given:

Marked price = ₹ 2400

Discount = 15%

Profit = 20%

Formula Used:

Selling Price = $$\text{Marked Price} \times \left(1 - \frac{\text{Discount}}{100}\right)$$​​

Profit % = $$\frac{\text{Selling Price} - \text{Cost Price}}{\text{Cost Price}} \times 100$$​​

Solution:

Selling price =$$2400 \times \left(1 - \frac{15}{100}\right)$$​

​$$= 2400 \times 0.85 = 2040$$​​

Cost price = $$\frac{2040}{1 + 0.20}$$​

​$$= \frac{2040}{1.20}$$​​

= ₹1700 

Alternate Solution: 

​$$\frac{MP}{CP} =\frac{100+Profit\%}{100 - Discount\%} \\ \ \\ \frac{2400}{CP} = \frac{120}{85} \\ \ \\ \implies CP = \frac{2400 \times 85}{120} = ₹1700$$