Number Grid

Answer

39

Why it works

Subtracting 19 and 11 from 69 gives 39.

1. The first row totals 69: 35 + 7 + 27.
2. The second row, both complete columns, and both complete diagonals also total 69.
3. The last row must follow the same pattern, so 19 + ? + 11 = 69.
4. Subtracting 19 and 11 from 69 gives 39.