Question

After the announcement of a sale, a bookstore sold 1/2 of all its books in stock. On the following day, this bookstore sold 4,000 more books. Now only 1/10 of the number of books in stock before the sale remain in the store. How many books were in stock before the announcement of the sale?

Answer 1

Answer:

155

Step-by-step explanation:

Let p represent the number of paperback books sold. Then p-60 is the number of hardback books sold. Total revenue will be the sum of products of price and quantity.

 2.99p +3.49(p-60) = 795 . . . . . an equation for total revenue

 6.48p -209.40 = 795.00 . . . . . simplify

 6.48p = 1004.40 . . . . . . . . . . . . add 209.40

 1004.40/6.48 = p = 155 . . . . . . divide by the coefficient of p

The owner sold 155 paperback books.