{"product_id":"puzzle-box-volume-1","title":"Puzzle Box Volume 1","description":"\u003cdiv\u003e\n\u003ci\u003eMultiplying 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?\u003cbr\u003eOn my broken calculator with keys + - ÷ x =, the only functional number is 7. How can I get 34 to appear in the readout?\u003cbr\u003eA 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?\u003cbr\u003e\u003c\/i\u003eThese and almost 300 other mathematical puzzles appear in this original collection, devised by world-renowned mathematicians, puzzle creators, and devoted puzzle lovers. A unique puzzle project, it unites the efforts of a dozen authors, including software engineer Andrea Gilbert and Bram Cohen, author of the P2P BitTorrent protocol. \u003cbr\u003eSeventeen different types of challenges include 3-D puzzles, chess puzzles, connections, dissections, foldings, geometrical puzzles, logic problems, matchstick puzzles, mazes, moving pieces, number puzzles, put-togethers, strimko, sudoku, visual puzzles, weightings, and word puzzles. The difficulty level of each puzzle is marked by stars, ranging from 2 to 5. Average difficulty level is about 3 stars, promising puzzle enthusiasts many entrancing hours of solving and enjoyment.\u003c\/div\u003e","brand":"Dover Publications","offers":[{"title":"Default Title","offer_id":44174708998445,"sku":"45565","price":16.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0034\/6521\/6073\/products\/dopu9780486810041.jpg?v=1740173500","url":"https:\/\/eurekapuzzles.com\/products\/puzzle-box-volume-1","provider":"EurekaPuzzles","version":"1.0","type":"link"}