Which number will best complete the relationship given below?
12 : 30 :: 20 : ?

Select the set in which the numbers are related in the same way as the numbers of the following sets. (Note: Operations should be performed on whole numbers without breaking them into their constituent digits. For example, consider 13. Operations such as adding to/subtracting from/multiplying 13 can be performed only on 13. Breaking 13 into 1 and 3 and then performing mathematical operations on 1 and 3 is not allowed.)
(424, 212, 212) (508, 302, 206)

Two sets of numbers are given below. In each set of numbers, certain mathematical operation(s) on the first number results in the second number. Similarly, certain mathematical operation(s) on the second number results in the third number and so on. Which of the given options follows the same set of operations as in the given sets?
(NOTE: Operations should be performed on the whole numbers, without breaking down the numbers into their constituent digits. E.g. 13 – Operations on 13 such as adding / subtr acting/multiplying to 13 can be performed. Breaking down 13 into 1 and 3 and then performing mathematical operations on 1 and 3 is not allowed.)
5 – 25 – 35 – 55; 13 – 169 – 179 – 199

Select the option that is related to the third number in the same way as the second number is related to the first number.
8: 72 :: 10: ?

11 is related to 132 by certain logic. Following the same logic, 9 is related to 110. To which of the following is 6 related, following the same logic?

The first two numbers are related in a certain way. Choose the correct option to replace the question mark (?) having the same relationship with the third term. 7 : 81 :: 13 : ?

Choose one number which is similar to the numbers in the given set.
 Given set: 435, 147, 642, 192

Find the related number to complete the analogy: 5 : 18 :: 8 : ?

Select the set in which the numbers are related in the same way as are the numbers of the following sets.
(Note: Operations should be performed on the whole numbers, without breaking down the numbers into their constituent digits. E.g., 13 – Operations on 13 such as adding/subtracting/multiplying to 13 can be performed. Breaking down 13 into 1 and 3 and then performing mathematical operations on 1 and 3 is not allowed.)
(19, 31, 55)
(14, 26, 50)