Where was the launch and keel laying ceremony of the 25T

Some equations are solved based on a certain system. On the same basis find out the correct answer for the unsolved equation.  

Select the option that is related to the third letter-cluster in the same way as the second letter-cluster is related to the first letter-cluster.

In the following question, select the related number from the given alternatives.

68 : 70 :: 45: ?

Complete the analogy.

54 : 45:: 73 : ?

Hill is related to mountain in the same way as

Four letter-clusters have been given, out of which three are alike in some manner and one is different. Select the letter-cluster that is different.

Select the option that is related to the third word in the same way as the second word is related to the first word.

Expand: Enlarge :: Condense: ?

Statements: N > U < I ≤ R < D < A; K ≥ O = G > X = E > A

Conclusions:

I. R < E

II. K > D

III. U ≥ X