A friend sent me this from her game
I tried many combinations and I cannot solve it for the life of me.
9 squares starting from each corner is (top left 61, top right 61, bottom left 69, bottom right 61 without the ?)
Down 30 11 41 23?
Across 20 35 29 21?
I tried adding, subtracting, this to an extent Find missing number in grid., etc.
What type of problem is this called? How do you solve it?
I told her to pick 20 since I see no pattern, but 20 is the only available number to keep the pattern for the numbers i added across and downward.