Answer
Let's think about it this way: Lyle takes his money and leaves the room. There's now A dollars. Bob takes 4 dollars from that and puts it in his pocket. There's now A-4 dollars. Bob's a little selfish, so he decides to take one third of the remaining money. So he takes 1/3*(A-4), and since he already had 4 dollars in his pocket, he's got 4+1/3*(A-4) dollars now.
prompt_id=24
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