Answer:
The correct answer is 144.
Explanation:
The librarian noticed that 60% of total seventh graders checked out fantasy books from the library.
Total number of seventh graders is given to be 240.
Number of seventh grade students who checked out fantasy books = 60% of 240 = 0.6 × 240 = 144.
Thus out of 240 seventh graders 144 of them would check out a fantasy book from the library.