Larry is in police custody for a suspected robbery. There is some evidence that he stole a watch out of a locker where he worked.
“What happened at the factory, Larry?” Chief Brossard asked. “I came to work at 5:00 am as I always do. We worked until noon when we ate lunch, which lasted an hour. I-” “What do you do at work?” “I cut metal slabs.” “How long does that take?”
“About one minute per strip. They’re for motor vehicles. Anyway, after lunch, I had exactly 179 strips to make. Three hours later, I came into the locker room to change and go home when I saw a locker broken into. Some people came in and accused me of stealing someone’s watch. I didn’t have time to steal it because when I got off at 3:59 other people would have seen me as an entire shift got off, and a minute to get there and break into the locker wasn’t enough time.” With fingerprint evidence, Chief Brossard’s suspicion was true that Larry stole the watch. How did he do it?
Solution
Each cut only took one minute. When he came to the 178th cut, that would automatically make 179 pieces without another cut. He then had two minutes to run to the locker room and break into the locker, stealing the watch.