Find the missing number:
2, 6, 12, 20, ?, 42

The correct option is 30.

To find the missing number in the given series, let us analyze the pattern or the difference between consecutive terms.

Given series: 2, 6, 12, 20, ?, 42

Let us calculate the difference between adjacent terms:

6 - 2 = 4
12 - 6 = 6
20 - 12 = 8

We can observe that the differences between consecutive terms are increasing consecutive even numbers: 4, 6, 8, ...

Following this pattern, the next difference should be 10, and the difference after that should be 12.

Now, let us calculate the missing term by adding 10 to the previous term (20):

$20+10=30$

To verify, let us add 12 to 30 to check if we get the next number in the series (42):

$30+12=42$

Since this matches the final term of the given series, the missing number is indeed 30.