TITLE: Chased by a lion and other pursuit-evasion problems
QUESTION [15 upvotes]: I am looking for a reference (book or article) that poses a problem that seems to be a classic, in that I've heard it posed many times, but that I've never seen written anywhere: that of the possibility of a man in a circular pen with a lion, each with some maximum speed, avoiding capture by that lion. 
References to pursuit problems in general would also be appreciated, and the original source of this problem.

REPLY [5 votes]: The book is Coffee in Memphis by Bollobas. It's the first problem, and there are loads more :
http://www.amazon.com/Art-Mathematics-Coffee-Time-Memphis/dp/0521693950