You have four puzzle books on your shelf, and you decide to arrange them in every possible order, moving one book every 30 seconds. How long will it take to arrange all the books?
Show answer & explanation
Correct answer: B
Explanation
Number of ways to arrange 4 books = 4! = 24
Time per arrangement = 30 seconds
Total time = 24 × 30 = 720 seconds
Convert to minutes:
720 ÷ 60 = 12 minutes
Hence, the correct answer is option 2.