h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

This is an old one you don't hear very often these days since few people roll their own cigs anymore.

This fellow notices he's getting low on tobacco and decides to make it last as long as he can. He's done this several times and knows what to do. He has enough tobacco to roll 16 cigarettes. When he finishes a cigarette he saves the butt. He can use the tobacco from 4 butts to roll one more.

How many cigarettes will he smoke before he's out?


(This is a fairly easy one so there is no need to post the answer. )

I was just thinking of that myself!