Three friends – a lawyer, a doctor, and a mathematician – decide to go on a camping trip. As they were setting up their tents, they realize they only have one pack of matches to start a fire.
The lawyer says, "I know! Let's start the fire with a briefcase full of legal documents. It will burn easily."
The doctor scoffs, "No, that's a waste of documents. Let's start the fire with some medical supplies. It will catch fire quickly."
The mathematician shakes his head and says, "Actually, I have a better idea. Let's start the fire by lighting a bicycle tire on fire. It's simple and efficient."
The lawyer and doctor look at him in disbelief. "Why a bicycle tire?" they ask.
The mathematician smirks and replies, "Well, it's simple really. Because a burning bicycle tire is a perfect example of a 'firecycle.'"