Select the missing number from the options given below.

A is 13th from the top, B is 18th from the bottom. When A and B change their position then A becomes 21th from top. What is the new position of B from bottom? 

How many pairs of letters are there in the word ‘CAMARADERIE’ which have as many letters between them as they have between them in the English alphabet?

In a certain code, PENCIL is coded as NEPLIC. What will be the code of the word BASKET?

A class of boys stands in a single line. One boy is nine tenth in order from both the ends. How many boys are there in the class? 

If in a certain code, GAMBLE is coded as FBLCKF, how is FLOWER coded in that code?

Vimal is the son of Mikka, and Nina is the daughter of Milan. Milan is the sister of Mikka. Who is Milan to Vimal? 

Find the wrong number in the series.
2, 9,5, 36, 125, 648