Answer:

The given number pattern is: 6, 12, 18, ?, 30, 30

To find the missing number, we need to observe the pattern and try to identify the rule that governs the sequence.

Observations:
- The numbers in the pattern are increasing.
- The first three numbers in the pattern follow a common rule: they are all multiples of 6.
- The last two numbers in the pattern are the same: 30.

Finding the Rule:
To find the rule, we can subtract each number from its previous number in the sequence:

12 - 6 = 6
18 - 12 = 6
? - 18 = ?

From the above calculations, we can see that the difference between each number is 6. Therefore, the rule for the first three numbers is adding 6 to the previous number.

Applying the Rule:
To find the missing number in the pattern, we can add 6 to the previous number, which is 18:

18 + 6 = 24

So, the missing number in the pattern is 24.

Verification:
Now, let's verify the answer by checking the rest of the pattern:

24 - 18 = 6
30 - 24 = 6
30 - 30 = 0

As we can see, the differences between each number in the pattern are consistent, confirming that 24 is the correct missing number.

Conclusion:
The missing number in the given number pattern is 24. Therefore, the correct answer is option A) 24.