Math Puzzle No. 5: The Damsel in Shining Armor
Long ago, damsels in shining armor battled dragons and rescued knights in distress on a daily basis. This ultimately lead to the complete extinction of dragons, a major catastrophe for the business of thrilling heroics! Although many of the surviving stories don't stress it, the rescues frequently involved logical thinking and problem-solving. Once upon a time, a knight was captured by an evil dragon and imprisoned in a castle that was surrounded by a square moat. The moat was infested with extremely hungry and alligators, piranhas, and -- just for good measure -- a few sharks. The moat was exactly 20 feet across and had no drawbridge or any other means of safely crossing. After a long time, a damsel appeared, carrying two wooden beams, each 19 feet 8 inches long and 8 inches wide. The beams were strong enough to walk across, but wouldn't reach across the moat. The knight was despondent. He'd already waited for weeks to be rescued. Now he'd have to wait more, unti