Number analogy Reasoning

Select the option that is related to the fifth letter-cluster in the same way as the second letter-cluster is related to the first letter cluster and the fourth letter-cluster is related to the third letter-cluster.
 GAIN : HBKP :: ACHE : BDJG :: CAKE : ?

Select the set in which the numbers are related in the same way as are the numbers of the following set. (NOTE: Operations should be performed on the whole numbers, without breaking down the numbers into its constituent digits. E.g., 13 – Operations on 13 such as adding /subtracting /multiplying etc. to 13 can be performed. Breaking down 13 into 1 and 3 and then performing mathematical operations on 1 and 3 is NOT allowed).
 (25, 9, 56)
 (13, 14, 183)

Select the option that is related to the fourth term in the same way as the first term is related to the second term and the fifth term is related to the sixth term.
 8 : 496 :: ? : 204 :: 9 : 711

Select the set in which the numbers are related in the same way as are the numbers of the given set.
 (NOTE: Operations should be performed on the whole numbers, without breaking down the numbers into its constituent digits. E.g. 13 – Operations on 13 such as adding / subtracting / multiplying etc. to 13 can be performed. Breaking down 13 into 1 and 3 and then performing mathematical operations on 1 and 3 is not allowed.)
(9, 81, 729)
(14, 196, 2744)

Select the option that is related to the fifth term in the same way as the second term is related to the first term and fourth term related to third term.
 14 : 21 :: 6 : 9 :: 12 : ?