Henry Ernest Dudeney/Puzzles and Curious Problems/241 - A Hurdles Puzzle

by : $241$

 * A Hurdles Puzzle
 * The answers given in the old books to some of the best-known puzzles are often clearly wrong.
 * Yet nobody ever seems to detect their faults.
 * Here is an example.


 * A farmer had a pen made of fifty hurdles, capable of holding a hundred sheep only.
 * Supposing he wanted to make it sufficiently large to hold double that number, how many additional hurdles must he have?


 * Perhaps our readers might be interested in making a list of old puzzles that are wrong.