What number should replace the question mark?
Check diagonally opposite sums.
Start from area right of ?
pairs are like this 15 19 17 21 15 19
so next pair is 17 21
for 21, ? should be 7 that is 8+6+7=21
27 28 32 93 54 40 48 64 48 67 84 64 55 50 ?
28 -> 9
52 -> 15
84 -> 23
20 -> 7
100 -> ?
83517
52649
30868
21781
0908?
