Find the missing number in the pattern shown in:

Let us analyze the mathematical relationship between the numbers in each of the three diagrams from Q.83 in image_146f63.png:
In each diagram, there are two upper circles (Top-Left and Top-Right), one central circle (Middle), and one lower circle (Bottom).

Let's find the pattern using the first two completed sets:

First Diagram:

* Top-Left = $93$
* Top-Right = $27$
* Middle = $63$
* Bottom = $3$

The relationship is:

$$(\text{Top-Left}-\text{Top-Right})-\text{Bottom}=\text{Middle}$$

$$(93-27)-3=66-3=63$$

Second Diagram:

* Top-Left = $79$
* Top-Right = $38$
* Middle = $37$
* Bottom = $4$

Applying the same formula:

$$(\text{Top-Left}-\text{Top-Right})-\text{Bottom}=\text{Middle}$$

$$(79-38)-4=41-4=37$$

The pattern holds true for both diagrams. Now, let's apply it to the Third Diagram to find the missing value ($?$):

* Top-Left = $67$
* Top-Right = $16$
* Middle = $42$
* Bottom = $?$

Using the same relation:

$$(\text{Top-Left}-\text{Top-Right})-\text{Bottom}=\text{Middle}$$

$$(67-16)-?=42$$

$$51-?=42$$

$$?=51-42=9$$

Thus, the missing number is 9.