Dr. Jones kept an antique clock in his office waiting room. One day after lunch he had only four patients. When he had returned from lunch the clock was still in the waiting room, but after the fourth patient left and Dr. Jones passed through the waiting room again, he noticed the clock was missing.

The police questioned the four afternoon patients, but they had gotten together and decided that every statement they would make would be a lie.

Adam said: None of us stole the clock. The clock was still there when I arrived.
Bert said: I arrived second. The clock was missing when I arrived.
Charlie said: I arrived third. The clock was still there when I left.
David said: The clock was missing when I arrived.

In what order did the patients arrive, and who stole Dr. Jones' clock?

I came up with solution suggested by many by assuming one patient came and left before the next patient arrived.  But I thought about the fact (as was suggested by someone else) that there is a posibility that one patient arrived before the last left.  Especially Charlie's statement made me clue in to that.  No matter what though, by getting together and deciding they would all lie, that certainly makes them accomplices and guilty in my book. 

Of course some doctors are pretty big crooks. Maybe he stole his own clock. Or maybe one of the patients cleaned his clock.  Because he cheated them. Or maybe one of the patients is a lawyer or insurance agent, certainly it would have had to have been him.

The problem is rated a 2 for difficulty, so maybe no trick.

Edited on July 10, 2007, 10:13 am

Edited on July 10, 2007, 10:49 am

Posted by jduval on 2007-07-10 00:23:53