Verbal Reasoning - Mental Ability Questions

First girl facing North
Then she rotates 100 deg clock wise => 10 deg ES
Then again she rotates 190 deg anti clock wise => for 100 deg it is North and more 90 deg means West.
Therefore, the new direction of the girl is West.

Carbon dioxide reacts with lime water (calcium hydroxide) to form milky precipitate of calcium carbonate 

Q, the Doctor, is the father of T. S, the Housewife, is the grandmother of T and hence the mother of Q. Since there are only two married couples one being that of Q, the grandfather of R. i.e, U must be married to S. Thus, R and T will be both children of Q and these must be the students So, P, who remains, shall be the wife of Q and she alone can be the nurse. Thus, U must be the contractor 

Clearly, for definite the males are Q, the father and U, the grandfather 

To find the rank from other end, we need to know the total number of students in the class. So. I is sufficient. Also: from II, we can conclude that there are (10 + 38- 1 = 47) students in the class.

So. II alone is also sufficient. 

Silver is a good conductor of electricity but it is not used to make electric wires because it is expensive 

A person will stand on the 'floor' and 'floor' is called 'roof'.

So, a person will stand on the 'roof'.

S is daughter of P and sister of T. So, T is daughter of P. 

Now, the sister of P is the daughter of M. This means that P is also the daughter of M. Clearly, T is the granddaughter of M. 

So, M is the Grandfather or Grandmother of T.