The number of books sold is 473.
<u>Step-by-step explanation:</u>
- The original cost of each book = $0.64
- The selling price of each book = $0.75
The difference between the original price and selling price of the book gives the profit per book.
The profit of one book = Selling price - Original price
Let,
- The total number of books be 'x'.
- The number of books sold be 'y'.
- The unsold books is 100.
- The total profit is -12 because it was gone to a loss of $12.
Therefore, the equation is formed as
total Profit = 0.75y - 0.64x
⇒ 0.75y - 0.64x = -12 --------(1)
Total books = sold books + unsold books
x = y + 100
⇒ x-y = 100 -------(2)
Substitute x= 100+y in the eq(1),
0.75y - 0.64(100+y) = -12
0.75y - 64 -0.64y = -12
0.11y = -12 +64
y = 52 / 0.11
y = 472.7
y ≅ 473
The number of book sold is 473 books.
The total number of books is (100+473) = 573 books.
