What number should replace the question mark?

The correct answer is Option (1) → 5

Look at the pattern in the first two figures.

Rule:

Center number = (Top-Left + Bottom-Right) − (Top-Right + Bottom-Left)

Check:

First figure

• (13 + 5) − (4 + 12)
• 18 − 16 = 2

Second figure

• (23 + 32) − (9 + 22)
• 55 − 31 = 24

Apply to the third figure:

• (2 + 24) − (9 + 12)
• 26 − 21 = 5