Question

Your school librarian has asked your class for some help on the

purchase of some new bookcases with two shelves each. She has
300 new books she needs to shelve. One half of the books are half
an inch thick. One third of them are one fourth of an inch thick,
and the rest are three fourths of an inch thick. Her shelves are
30 inches long. How many bookcases should she buy?

Answer 1

The librarian should buy approximately 6 bookcases to shelve the 300 new books.

Step-by-step explanation:

To determine the number of bookcases the librarian should buy, we need to calculate the total thickness of all the books and divide it by the available shelf length. Let's calculate:

Number of books that are half an inch thick: 300 / 2 = 150 books

Number of books that are one fourth of an inch thick: 300 / 3 = 100 books

Number of books that are three fourths of an inch thick: 300 - (150 + 100) = 50 books

Total thickness of books: (150 * 0.5) + (100 * 0.25) + (50 * 0.75) = 175 inches

Number of bookcases needed: 175 / 30 = 5.83 approximately 6 bookcases