Forty-eight computer-generated brain teasers, with numbers as themes. "Triskaidekaphobia" (abnormal fear of the number 13) asks puzzlers to accumulate 13 points

Who knew that being invaded by aliens could be so much fun? Kids can help wacky extraterrestrials find the United Nations, capture a runaway brain, and more. 33

Forty-eight challenging mazes ? each with one half mirroring (almost) the other half. Includes The Walls of Jericho, Jabberwocky, The Mirror Cracked, Church Win

Originally published in English by: Moscow: Foreign Languages Pub. House, 1957.

Combines two previously published works, resulting in ninety-three brain-teasing puzzles, riddles, and questions with an emphasis on humor.