Six girls are standing in such a way that they form a circle, facing the centre. Subbu is to the left of Pappu, Revathi is between Subbu and Nisha, Aruna is between Pappu and Keerthana. Who is to the left of Pappu?

According to question,
We can draw a figure , in which Mohan is between Balu and Raju and Raju is to the immediate right of Praveen and Amith is to the right of Balu.
As shown in figure , Amith is in extreme right end .
Sitting arrangement :-

According to question,
We can draw a figure , in which C is between A and E. B is just to the right of E but left of D. F is not at the right end.
From given figure it is clear that , F is to the left of A.
Sitting arrangement :-

According to question,
We can draw a figure , in which C is between A and E. B is just to the right of E but left of D. F is not at the right end.
From it is clear that , F is at the left end .
Sitting sequence :-

Draw a figure on the basis of above given question ,
A is right side of B and left side of C. O is in the right side of A. B is right of D.
As shown in figure , A house is in the middle
Sitting sequence :-

Draw a figure on the basis of above given question ,
T is on the right of Z. M is on the left of Z but is on the right of L .T is on the left of Q.
As shown in figure , L is sitting first from the left .
Sitting sequence :-

Draw a figure on the basis of above given question ,
the father was found to be sitting to the left of the son and right to the grandfather. Mother was sitting to the right of her daughter but left to the grandfather.
As shown in figure , Grandfather is occupying the central place .
Sitting arrangement :-

Draw a figure on the basis of above given question ,
S is between T and Q and Q is to the immediate left of R. P is to the immediate left of T.
As shown in figure , S is in the middle.
Sitting arrangement :-

Draw a figure on the basis of above given question ,
Y is at the left of X, W is sitting at the right of Z. V is sitting at the right of X and W is sitting at the left of Y. If Z is sitting at one end of the row .
From figure , It shows that Y is in the middle.
Sitting arrangement :-

According to question,
We can draw a figure , in which A and B are sitting face to face. D is not sitting next to A but can see the facial expression of A clearly. B is talking to C who is sitting opposite to him.
From given figure it is clear that , A and C are sitting together.
Sitting arrangement :-

According to question,we have
Rashi's position = 15th from the left
Ramesh's position = 29th from the right
After interchanging their positions ,
Rashi's position = 26th from left
? Total number of students = Rashi's position + Ramesh's position - 1
Total number of children in the row = 26 + 29 ? 1 = 54
As shown in figure -