Verbal Reasoning - Mental Ability Questions

The correct order is :   

Newly married Couple     Family    Caste    Clan    Species

                      3                        2                1             4             5

Two series alternate here, with every third number following a different pattern.
In the main series, 4 is added to each number to arrive the next.
In alternate series, 5 is subtracted from each number t arrive the next number.
Here in the main series
3 + 4 = 7
7 + 4 = 11
11 + 4 = 15
15 + 4 = 19

In alternate series
24 - 5 = 19
19 - 5 = 14...

Given series follows the rule of

1050/2.5 = 420
420/2.5 = 168
168/2.5 = 67.2
so 67.2/2.5 = 26.88

P, Q, R are children of same parents. So. S who is R's mother and T, who is R's father will be mother and father of all three. 

However, it is not mentioned whether Q is male or female So, D cannot be definitely true. 

D is father of A and grandfather of F. So, A is father of F. 

Thus. D and A are the two fathers. C is the sister of F So. C is the daughter of A. 

Since there is only one mother, it is evident that E is the wife of A and hence the mother of C and F. 

So, B is brother of A There are three brothers. So. F is the brother of C. 

 Clearly, A is E's Husband.