Which is the odd number-pair?

In each of the following questions, select the related word/ number/ letter from the given alternatives.

Heart : Cardiologist : : Eye : ? 

Which letter will come in place of the question mark (?) in the following series?
FLO, H?Q, JPS, LRU

Choose the alternative which resembles the mirror image of the given combination.

Position of Dices are given below:

Identify the number when top is 5 what will be at bottom?

Mr X starts to walk 3 km towards East then he turns to his right and walks 4 km. Again he starts to walk 5 km towards East after that he turns to his left and walks 6 km. Finally he turns towards West and walks 8 km.If Mr X walked towards North from his starting point then, how much he covered the distance to reach the last point?

If “P” denotes “divided by”, “R” denotes “added to”, “S” denotes “subtracted from” and “Q” denotes “multiplied by”, then
48 P 4 R 3 Q 4 S 6 Q 4 = ?

In the Jhanke rank, Prabha is 12 places ahead and Prabha is 15th from the last student. If the tableau is 4th in order of merit, then how many students are there in its class?