Tracy has a charity book collection store from which she receives book donations from members of her town. Any person who wants to borrow a book is free to do so as long as they return the book after they've finished reading. She has already received 300 book donations. If ten people come and donate five books each in a week, and a total of 140 books are borrowed by other people to read, calculate the total number of books she has remaining in the store?
Thoughts? Step-by-step reasoning:
The ten people donated 10 * 5 = 50 books. The total number of books in her store after the new donations is 300 + 50 = 350 books. When some of the books are borrowed, her total collection becomes 350 - 140 = 210 books.
Thus, the answer is 210.