What gets wetter and wetter the more it dries? What can you catch but not throw? What goes around the world but stays in a corner? No sooner spoken than broken. What is it?* If you enjoy a challenge, then today's mind-bending riddle sites are for you. [Editor's Note: An updated version of this topic can be found here: Riddles]
"Puzzles For the Brain To Gnaw On." Brain Food's puzzle collections includes hundreds of problems organized into seven categories: Logic Puzzles, Word Puzzles, Lateral Thinking Puzzles, Tricky Puzzles, Word Boxes, Numbered Puzzles, and Logi-Number Puzzles. You'll find the Groaners listed under Tricky Puzzles. "I have two U.S. coins that add up to fifty-five cents. One is not a nickel. What are they?" Click Solution to reveal "A nickel and a half dollar. Only one is not a nickel." I can hear you groaning from here.
These brain teasers are mathematical puzzlers that require logical thinking. Three new teasers for grades three through seven are posted each Wednesday, along with the previous week's answers. If you crave more puzzles, prowl the archives for three week's worth of questions and answers. "In solving the Brain Teasers it helps to have a working procedure. You might want to consider this four-step procedure: Understand, Plan, Try It, and Look Back."
"Scientists get to solve puzzles every day, because science and research involve finding solutions from the clues that we are given. Just like with brainteasers and riddles, the answers to science mysteries are not always easy to see at first. With time and effort, they eventually become clear." Unique sections in this National Institute of Environmental Health Sciences site are Palindromes, Optical Illusions, and the Mind Over Matter trick.
The Mind Breakers want to "brighten up your grey brain cells" with the best in puzzles and riddles. Each of their listed puzzles is rated for "coolness" and complexity on a scale of one to four. Call me uncool, but I couldn't tell what made one riddle cooler than another. Temperature aside, navigation around the site is simple, and answers are supplied. Be warned, however, some of the riddles have trick answers.
William Wu, a graduate student at Stanford University, has created my pick-of-the-day riddle site for high-school students and adults, especially those with an interest in math or computer science. Because he doesn't want to "spoil the problem-solving experience for many visitors," answers are not available at the site. Rather, they are posted to the community forum, where you can search for them via the forum search function. Some riddles do, however have hints. To view them, click and drag your mouse over text area to the right of the "Hint" label.