A publisher printed 2000 copies of a book at a cost of Rs. 70000. He distributes 400 copies free as specimen copies. He ave 30% discount on marked price of each book which is Rs. 75. What is his gain or loss percent age = ?

Explanation:-

According to the question,
Cost price of 2000 books are = Rs. 70000
Cost price of 1 book is $$= \frac{{70000}}{{2000}} = {\text{Rs}}{\text{. 35}}$$ Marked price of 1 book is = Rs. 75
Discount = 30%
Selling price of 1 book = Rs. 52.5
He distribute 400 books free
Selling price of 1600 books = 52.5 × 1600
= Rs. 84000
Profit = Selling price - Cost price
= 84000 - 70000
= Rs. 14000 $$\eqalign{ & {\text{Profit }}\% = \frac{{14000}}{{70000}} \times 100 \cr & \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = 20\% {\text{ gain}} \cr}$$