Question

Fill in the blank

$\begin{array}{ccc}7& 6& 8\\ 9& 8& 4\\ 10& 4& ....\end{array}$

Answer 1

In this example, the sum of the numbers in each horizontal row is 21.
$7+6+8=21$
$9+8+4=21$
The missing number is 7 such that,
$10+4+7=21$