A question about the mindset of lawyers. Need this "Example" explained

I am planning to be a lawyer in the future and i am reading a book about lawyers and law. In this section "How to think like a lawyer" There was an example. The example was"

"A manual labor worker, a mathematician and a lawyer were invited into a test. They were asked "What is Two + Two"

The manual labor worker took a while to think and he answered "4"

The mathematician took a little time to think and he answered "4.0"

Then finally came the lawyers turn. He immediately answered "Where do you want the answer to be?""

I still haven't figured out what exactly this means?