Reply To: Maths
4: [possible numbers are 1,2,3,4,5,6,7,8,9]
top row: 1+2+3 = 6
using this, this would mean that 1+4+bottom right square should be 6
however, the only possibility the the bottom right square is 1, which is already used
therefore, the square has no solutions
5: x=7
6:15,01,11
05,09,13
07,17,03