In a certain code of language - 

‘A × B’ means ‘A is B’s brother’.
‘A ÷ B’ means ‘A is B’s sister’.
‘A + B’ means ‘A is B’s father’.
‘A – B’ means ‘A is B’s mother’.
Using the same meaning of the mathematical operators as given above, which of the following means ‘X is Z’s mother’s father’? ​​

Solution:

From the given options - the family tree is given below as - 

(A) X + Y – Z 

(B) X – Y + Z

(C) X + Y × Z

(D) X × Y + Z

'X + Y - Z' translates to 'X is Y’s father' and 'Y is Z’s mother'.
Therefore, X is Z’s mother’s father.

Therefore, the answer is (a) X + Y- Z. ​​​​