Verbal Reasoning - Mental Ability Questions

In a certain code language, '+' represents 'x', '-' represents '+', 'x' represents '÷' and '÷' represents '-'. What is the answer to the following question?
25 + 10 ÷ 240 x 16 = ?

In a certain code, 592 means 'grapes are sweet', 374 means 'I like oranges' and 267 means 'oranges are sour'. Which digit represents sour?

If 4 * 5 % 3 = 8000 and 2 * 3 % 2 = 36, then 4 * 3 % 3 = ?

In the following question, select the related word from the given alternatives.
Ampere : Electric current : : Fathom : ?

In each of the following questions three statements are given and these statements are followed by two conclusions numbered (1) and (2). You have to take the given three statements to be true even if they seem to be at variance from commonly known facts. Read the conclusions and then decide which of the given conclusions logically follows from the two given statements, disregarding commonly known facts.
Statements:

All books are novels.
No novel is a magazine.
All magazines are newspaper.
Conclusions: 

I.No book is a magazine.
II. Some newspaper are novels.

In a certain code language, '+' represents 'x', '-' represents '+', 'x' represents '÷' and '÷' represents '-'. What is the answer to the following question?

45 x 5 + 2 - 20 = ?

In this question, some equations are solved on the basis of a certain system. On the same basis find out the correct answer from amongst the four alternatives for the unsolved equation.

53 ­ 34 = 5334
65 ­ 46 = 6456
75 ­ 24 = ?

P is the brother of Q. Q is the brother of R. P is the son of S. Based these three statements, much of the following statements cannot be definitely true?