Libros de Peter Grabarchuk (2 libros)

Multiplying my age by 6 then subtracting 6 produces the same result as subtracting 7 from my age then multiplying by 7. How old am I? On my broken calculator with keys + - ÷ x =, the only functional number is 7. How can I get 34 to appear in the readout? A country mints four denominations of coins, in whole numbers of cents. It takes four of these coins to make 21¢, or 24¢, or 25¢, or 26¢. What are the denominations of the coins? These and almost 300 other mathematical puzzles appear in this original collection, devised by world-renowned mathematicians, puzzle creators, and devoted...

These 300 original and full-color exercises include 3-D puzzles, chess puzzles, connections, dissections, foldings, geometrical puzzles, logic problems, matchstick puzzles, mazes, moving pieces, number puzzles, put-togethers, strimkos, sudoku, and visual and word challenges. Solutions.