Select the option that is related to the fifth number in the same way as the second number is related to the first number and the fourth number is related to the third number.
20 : 42 :: 25 : 52 : : 18 : ?

Logic: The second number is obtained by multiplying the first number by 2 and then adding 2.

First Pair: 20 : 42
Multiply 20 by 2, then add 2:
20 × 2 + 2 = 42

Second Pair: 25 : 52
Multiply 25 by 2, then add 2:
25 × 2 + 2 = 52

Now, apply the same pattern to the third pair (18 : ?):
Multiply 18 by 2, then add 2:
18 × 2 + 2 = 38

So, the missing number is 38.​​