Which one will replace the question mark of the given diagram above?

The correct answer is 38.

Rule: in each figure, the number in the centre equals the sum of the four outer numbers, minus 2. That is, Centre = (sum of the four corners) − 2.

Figure 1: corners are 0, 6, 2 and 4. Sum = 0 + 6 + 2 + 4 = 12, and 12 − 2 = 10, which is the centre value shown.

Figure 2: corners are 6, 2, 8 and 10. Sum = 6 + 2 + 8 + 10 = 26, and 26 − 2 = 24, which is the centre value shown.

Figure 3: corners are 4, 14, 10 and 12. Sum = 4 + 14 + 10 + 12 = 40, so the missing centre value is 40 − 2 = 38.

Therefore the question mark is replaced by 38.