Why can you not make a sudoku puzzle with all prime numbers?
I am assuming you are referring to a normal 3x3 sudoku grid,
where you can only use the numbers 1-9 once in the grid, and by
prime number you mean the 3digit number across and down the grid
must be prime? For a number to be prime, it must end in 1, 3, 7 or
9. There are 5 places on the Sudoku grid for a number to finish and
as you can only use a number once in sudoku you have one place left
where the number can not be prime. This means the most you can have
is 5 prime numbers.