Find the missing number?

Amit and Sohan have two brothers Manju Sohan and Amit's sister who has a son Ravi. So tell me how is Ravi related to Amit?

Direction: Select the related word from the given alternatives.

Nest : Bird :: Den : ?

DIRECTIONS: These questions are based on the following information.
Nine persons – J, K, L, M, N, O, P, Q and R – sit around a circular table facing different directions (towards the center or away from the center).O sits second to the right of J who sits adjacent to neither P nor K. L sits second to the right of both P and K and faces away from the center. M sits third to the right of Q who does not sit adjacent to O. N sits adjacent to neither J nor K. R is facing towards the center and neighbours of O face the same direction. Neighbours of M face different directions. R and M face different directions.

Who sits third to the right of K?

From the given alternatives select the word which cannot be formed using the letters of the given word
ADMINSTRATOR

If 'F' means '+', 'P' means '×', 'T' means '÷' and 'K' means '-' then 40 T 8 F 16 P 4 K 13 =?

A word is represented by only one set of numbers, as given in one of the alternatives. The numbers given in the alternatives are represented by two classes of letters, as in both matrices given below. The number of columns and rows of Matrix-I is given from 0 to 4 and that of Matrix-II from 5 to 9. A letter from these matrices can be represented first by its row and later by its column number. For example, 'Y' can be represented by 01, 33, 42 etc. 'H' can be represented by 56,75, 97 etc. Similarly you have to identify the group for the word MAIN
 

deb, ijg, nol, ? , xyv