- 1000 Hard Variety Puzzles . - Answers to every puzzle are provided. - Each puzzle is guaranteed to have only one solution. - Playing logic puzzle is not just a fun way to pass the time, due to its logical elements it has been found as a proven method of exercising and stimulating portions of your brain, training it even, if you will and just like training any other muscle regularly you can expect to see an improvement in cognitive functions. Some studies go as far as indicating regular puzzles can even help reduce the risk of Alzheimer's and other health problems in later life. Completing logic puzzle regularly helps the brain process both problem solving and improves logical thought process with the use of deductive reasoning, which can also be applied to approaching real life challenges in a different manner. Playing logic puzzle on a daily basis helps to keep an active mind and players often see improvements in their overall concentration.