Verbal Reasoning - Mental Ability Questions

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

hello, lower, error, organ, tense, ?

Select the related word/letters/number from the given alternatives.
30 : 16 :: 24 : ?

A series is given with one term missing. Select the correct alternative from the given ones that will complete the series.
KV, LU, MT, ?

Some books are arranged one above the other. If a book is at 18th position from the top and 5th position from bottom then the total number of books is

In a certain code language, "SIGHT" is written as "@?*^!" and "ANT" is written as "#&!". How is "NIGHT" written in that code language?

Which set of letters when sequentially placed at the gaps in the given letter series shall complete it?

T_ST_S_U_T_S

In the following question, select the related letters from the given alternatives.
JQXE : LSZG : : MTNL : ?

In each question below are three statements followed by two conclusions numbered I and II. You have to take the three given statements to be true even if they seem to be at variance with commonly known facts and then decide which of the given conclusions logically follows from the three statements disregarding commonly known facts.
Statements:
All numbers are digits.
All alphabets are numbers.
All words are alphabets.
Conclusions:
I. All words are digits.
II. Some numbers are not words.