Verbal Reasoning - Mental Ability Questions

A is the sister of B and B is the daughter of C.

So, A is the daughter of C. Also, D is the father of C.

So, A is the granddaughter of D. 

After dropping  vowels we have the following arrangement:

C B % 7 D $ B 5 C ? 3 D 9 @ 2 #

Hence, D is twelth from the left end of the above arrangement.

first letter A with last letter Z
similarly 2nd last letter Y with 2nd letter B
Now 3rd letter C with 3rd last letter X
4th last letter W with 4th letter D
and so on....

Therefore the missing letter is X

Fourth to the right of the tenth from the right means (10 - 4 = )6th from the right, ie 5. But according to the queswtion, one is subtracted from each of the numbers, ie 4. 

ten = 3(number of letters)
nine = 4(number of letters)
sixty = 5(number of letters)
ninety = 6(number of letters)
seventy = 7(number of letters)
sixtysix = 8(number of letters)
ninetysix=96(number of letters)

Then, likwise choose the number which has 9 letters in its Spelling.

When positions of first and the third alphabets of each of the words are interchanged, we have PAL  TUB  RAC  NOS  DIH

Clearly, PAL and TUB are the only meaningful words. These words are obtained from LAP and BUT respectively. 

If the first half of the English alphabet is reversed and the remaining part has been left undisturbed, then it becomes very easy to find out the required letters, if required letters come in the first half. According to the question, 10th to the left of 16th letter from the left = (16 - 10 =) 6th letter from the left in new series.

=>  6th letter from the left in new series = (13 + 1 - 6=) 8th letter from the left in the original series, i.e H.

Justification:   

In statements A and B, the common code word is 'na' and the common word is 'water'.

So, 'na' means 'water'.

In statements B and D, the common code word is 'jo' and the common word is 'life'.
So, 'jo' means 'life'.
Thus, in statements B, 'tod' represents 'is'.