For anyone interested in the science of secrecy and clandestine codes, renowned puzzle whiz Pierre Berloquin has created a collection of colorful exercises that gives amateurs an opportunity to test t
How smart are you? Find out with these 300 self-scoring exercises from one of the world's most-renowned creators of mind-bending conundrums. Pierre Berloquin organizes his mini puzzles into series, wi
There are three loops in a tangle of rope. How many are independent, and how many are interlocked?Two knights stand on a chessboard. How many other knights must you add so that each square is occupied
Follow the hour hand and minute hand of a clock for 24 hours. How many times do they form a right angle?Timothy's house has several rooms, each of which has an even number of doors, including doors th
