The sequence of numbers in his safe code is made up of the reversible primes, prime numbers that give another prime number when you reverse their digits.

This puzzle game tests mathematical skills and logical thinking as players embark on a journey to unlock a treasure hidden in ...

This optical puzzle challenges the viewer to find the hidden number '99' among a pattern of repeating '67' numbers. It tests ...

Solving 15 digits puzzle using IDA* method, with GUI. Run GUI.py to show the process. Run IDA_Star to run IDA*.

Which two numbers were multiplied with the calculator? Show puzzle solution The last digit of the product must be 7. Because the last digits of the two factors can be only 2, 3, 5, 6, 8 or 9 ...

The number 2025 can be split into two two-digit numbers: 20 and 25. If we add these together (20 + 25 = 45) and square the ...

These types of optical illusion puzzles have now become very popular ... a black and white image in which you will see a series of digits 6 written. Amongst the lot, you need to spot the number ...