12 : 30 : : 20:?

Let's analyze the given question "12 : 30 : : 20 : ?". The format presented suggests that there is a relationship between the two numbers in the first pair (12:30) that can be used to find the corresponding number in the second pair (20:?).

The pattern we observe is:

• For the first pair "12 : 30", we can break it down as follows:

12 = (3 * 2) + 3

This can be interpreted as the number 12 being split into the equation where 3 multiplied by 2 gives 6, and adding 3 results in 12.

• Similarly, for the second pair "30", we follow the same pattern:

30 = (5 * 2) + 5

Here, the number 30 is derived from multiplying 5 by 2 to get 10, and adding 5 gives us 30.

• For the third pair "20 : ?", we apply the same rule:

20 = (4 * 2) + 4

Breaking down 20 into (4 * 2) plus 4 results in 20. Now, to find the corresponding value for "?", we use the same method:

? = (6 * 2) + 6 = 12 + 6 = 42

Thus, the answer to "12 : 30 : : 20 : ?" is 42.