Five birds are sitting on a tree. The Pigeon is to the right of the Parrot. The Sparrow is above the Parrot. The Crow is next to the Pigeon. The Crane is below the Crow. Which bird is at the centre?

According to question,
We can draw a figure , in which E is to the left of B, but on the right of A. F is on the right of B but is on the left of G who is to the left of C.
From it is clear that , the members B and F are sitted right in the middle.
Sitting arrangement :-

Draw a figure on the basis of above given question ,
A is to the immediate left of B, but on the immediate right of D. Q is on the right of A but is on the left of S, and T is on the left of V , who is to the left of D.
As shown in figure , the member A is sitted right in the middle.
Sitting sequence :-

According to question,
We can draw a figure , in which A is on the right of B, E is on the left of B but on the right of C and A is on the left of D.
It is clear that E is second from the left .
Sitting arrangement :-

According to question,
We can draw a figure ,in which X is to the left of Y, but on the right of O. P is on the right of Y but is on the left of N and M is on the left of Z , who is to the left of O.
From given figure , it is clear that the member X is sitting right in the middle.

According to question,
Draw a figure ,as per the details of arrangement is given in above question ,
Hence , The position of B₂ and G₂ are 3^rd and 4^th .

Draw a figure on the basis of above given question ,
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.
As shown in figure , E is between B and C
Sitting sequence :-

Draw a figure on the basis of above given question ,
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.
As shown in figure , B and E are sitting by the side of D.
Sitting sequence :-

Draw a figure on the basis of above given question ,
The student E sitting at the centre is facing only C and the student A is sitting facing the back of E. If D is sitting on the right of E.
Hence , it is clear that B is sitting on the left of E .
Sitting sequence :-

Draw a figure on the basis of above given question ,
D is between A and C. B is just right of C but left of F. E is not at the right end.
From figure , It shows that F is at the right end.
Sitting arrangement :-

According to question ,
A is 7th from the left and B is 9th from the right.
After interchanging their positions ,
Now A becomes 11th from the left.
? Total number of people in the row = A's position + B's position - 1
Total number of people in the row = 11 + 9 ? 1 = 19