Find the missing number:

The correct answer is Option (2) → 36

The outer numbers form two opposite pairs, left with right and top with bottom, and the centre number links each pair: in each pair, the larger number is the smaller one multiplied by one more than the centre, \(8+1=9\).

• Left and right: \(45=5\times9\), so the rule holds

• Top and bottom: the top is \(4\times9=36\)