In the following question, select the number which can be placed at the sign of question mark ( ?) from the given alternatives .

Select the letter-pair that can replace the question mark (?) in. the following series
BA, DC, FE, HG, ? , LK

Directions: In each of the following questions, four words have been given, out of which three are alike in some manner and the for one is different. Choose out the odd one. 

Select the letter that will come next in the following series.
O, R, U, X, A, ___

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 : ' F ' can be represented by 01 , 13 , 32 , etc . and ' N ' can be represented by 57, 69, 95 etc. Identify the set for the word PEN.

If TREK = 8346 and FAMILY =209175 then REALITY will be 

In a certain code, TRIPPLE is written as SQHOOKD. How is DISPOSE written in that code ?

Find the missing number from the given responses.