Question closed.
In the image you can see some random number series. But there is a pattern to the numbers. Can you identify the pattern and find the number that will replace the question mark symbol ?
How many different numbers can you make if you use the digits 1, 2, 3, 4 once each, in any order, and a times sign. For instance 31x24, or 2x413.
How many ways can you find to make the number 10, by adding or subtracting prime numbers? The same numbers but in a different order count as the same answer. (Prime numbers are only divisible by themselves and 1 so they are 2, 3, 5, 7, 11, 13, ...)
