Verbal Reasoning - Mental Ability Questions

From statements I and II together, we can conclude only that either B is the sister or brother of A.

So, even from both the statements, the exact relation cannot be known. 

Train becomes trail when the "n" is replaced by an "l", and grain becomes grail when the "n" is replaced by an "l".

There were all parrots but six means that six birds were not parrots but only pigeons and koels.

Similarly, number of parrots + number of koels = 6 and number of parrots + number of pigeons = 6.

This is possible when there are 3 parrots, 3 pigeons and 3 koels i.e. 9 birds in all.

Deepak is the son of Ravi, who is the son of Rekha. 

Thus, Deepak is the son of Rekha 

A is the son of B and D is the son of the sister of B. So, A is the cousin of D. 

Clearly, the required number would be such that it leaves a remainder of 1 when divided by 3, 4, 5, or 6 and no remainder when divided by 7. Thus, the number must be of the form (L.C.M of 3, 4, 5, 6) x + 1 i.e., (60x + 1 ) and a multiple of 7. Clearly, for x = 5, the number is a multiple of 7. So the number is 301.