Follow the rules and eliminate every number from a given list, except one.
From the even numbers in the range 2-40 inclusive, eliminate:
- multiples of 4,
- single-digit numbers,
- numbers which are next to (one away from) a prime number or square number.
Which is the only number that remains?
The 7puzzle Challenge
The playing board of the 7puzzle game is a 7-by-7 grid containing 49 different numbers, ranging from 2 up to 84.
The 1st & 3rd rows of the playing board contain the following fourteen numbers:
2 9 13 14 15 22 25 36 40 42 45 66 72 80
What is the product of the two prime numbers?
Make 308 Challenge
Can you arrive at 308 by inserting 2, 4, 6, 8 and 10 into the gaps below?
(◯²×◯÷◯)–(◯×√◯) = 308
Answers can be found here.
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