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Help
If you have any questions, you are always welcome to contact us. We'll get back to you as soon as possible, withing 24 hours on weekdays.
Customer service
All questions about your order, return and delivery must be sent to our customer service team by e-mail at yourstore@yourdomain.com
Sale & Press
If you are interested in selling our products, need more information about our brand or wish to make a collaboration, please contact us at press@yourdomain.com
There are three loops in a tangle of rope. How many are independent, and how many are interlocked?Two knights stand on a chessboard. How many other knights must you add so that each square is occupied or threatened by a knight?Among six seemingly identical drawings of mandalas, each rotated by multiples of 60 degrees, one is different. Which is it, and why?Challenge yourself with these mindbenders, brainteasers, and puzzles. Each of them has been carefully selected so that none will be too tough for anyone without a math background but they're not too easy. Some are original, and all are clearly and accurately answered at the back of the book.
⚠️ WARNING (California Proposition 65):
This product may contain chemicals known to the State of California to cause cancer,
birth defects, or other reproductive harm.
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