Final answer:
The price of a paperback book is $4 and the price of a hardcover book is $12. Therefore, 1 paperback book was sold. The correct option is B) 12
Step-by-step explanation:
Let's assume that the price of a paperback book is x dollars. According to the information given, the price of a hardcover book is three times the price of a paperback, so the price of a hardcover book would be 3x dollars.
It is given that 40 hardcover books were sold for a total of $480. We can set up the equation 40(3x) = 480 to find the value of x.
Simplifying the equation, we get 120x = 480. Dividing both sides by 120, we find that x = 4. Therefore, the price of a paperback book is $4.
The combined sales of hardcover and paperback books totaled $600, so we can set up the equation 40(3x) + 40(x) = 600 to find the number of paperback books sold.
Substituting the value of x, we get 40(12) + 40(4) = 600. Simplifying the equation, we get 480 + 160 = 600. Subtracting 480 from both sides, we find that 160 = 120. Dividing both sides by 120, we find that x = 1.33. Therefore, approximately 1.33 paperback books were sold.
Since we can't have a fraction of a book, the closest whole number is 1. Therefore, 1 paperback book was sold.
In conclusion, 1 paperback book was sold. The correct option is B) 12