Verbal Reasoning - Mental Ability Questions

In the following question, which one set of letters when sequentially placed at the gaps in the given letter series shall complete it?

x_za_yza_xy_aa_

A series is given with one term missing. Select the correct alternative from the given ones that will complete the series.

RFT, QDQ, PBN, OZK, ?

From the given alternatives, select the word which CANNOT be formed using the letters of the given word.

Abettor

In a certain code language, 'x' represents '+', '÷' represents 'x', '-' represents '÷' and '+' represents '-'. Find out the answer to the following question.

5 ÷ 20 - 4 + 10 x 8 = ?

In the question, a word is represented by only one set of numbers as given in any one of the alternatives. The sets of numbers given in the alternatives are represented by two classes of alphabets as in two matrices given below. The columns and rows of Matrix I are numbered from 0 to 4 and that of Matrix II are numbered from 5 to 9. A letter from these matrices can be represented first by its row and next by its column, e.g., 'C' can be represented by 04, 40, etc., and 'K' can be represented by 56, 75, etc.
Similarly you have to identify the set for the word 'NICE'.

A series is given, with one word missing. Choose the correct alternative from the given ones that will complete the series.

Smart, Aspire, Castle, Abysmal, Accost, ?

If the first 10 terms and the last 10 terms of the given expression are interchanged in such a way that the first term is interchanged with the last, the second with the second last, the third with the third last and soon, what will the fifth term from the right be in the new arrangement?

RB75E%M3W48Q9#B2A$MS

Choose the pair which is related in the same way as the words in the first pair from the given choices.

DOG : KENNEL :: BEE : ___