Where was the first India-Nordic summit

Select the related word/letters/number from the given alternatives.

PQRS : TUVW : : MNOP : ?

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

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

31 : 90 :: 43 : ?

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

Select the set of letters that when sequentially placed in the blanks of the given letter series will complete the series.

_ x y _ w _ y z w x _ _ w _ _ z

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

Fungi: Mycology :: Insects:?

Select the combination of letters that when placed sequentially in the blanks of the given letter series will complete the series.

If 60 [15] 3 and 108 [63] 7, then what is the value of A in 156 [A] 16?