Think Tank: 36 Unusual Puzzles, by Don Rubin ISBN 0060909811
Five out of five stars
The 36 puzzles in this collection are difficult, largely because they are unusual. Many are based on visual identification and rearrangements, so it is possible for nearly all people to solve them given time, determination and a significant amount of scratch paper. In some cases, the best tactic would be to make a copy of the puzzle, cut out the pieces and then rearrange them until the solution is found.
For example, puzzle 19 has a series of 12 squares containing pieces of curved railroad tracks. The goal is to rearrange them to make a path from the start position in the lower left to the end position in the upper right.
Other puzzles rely on knowledge of pop culture. For example, number 14 has an image of dialog balloons taken from popular comic strips. If you are unfamiliar with the comics, then there is little hope of solving it. Of course, in the modern world of search engines, all you need to do is type the right text in the search window. Solutions to all puzzles are given at the end.
This is a fun book to look through, all the puzzles can be done with time, effort and persistent use of a search engine.