Consider the following: A, B, C, D, E, F, G and H are standing in a row facing North.
B is not neighbour of G.
F is to the immediate right of G and neighbour of E.
G is not at the extreme end.
A is sixth to the left of E.
H is sixth to the right of C.

Which one of the following is correct in respect of the above?

The correct answer is: G is to the immediate right of D.

Step-by-Step Explanation and Seating Arrangement:

We are given 8 people: A, B, C, D, E, F, G, and H standing in a row facing North. This means left is to the left-hand side and right is to the right-hand side.

Let's analyze the given clues step-by-step:

1. Use the clues with maximum distance:

Clue: "A is sixth to the left of E."

This means there are 5 people between A and E. In a row of 8 positions (1 to 8 from left to right):

- Position of A must be 1st or 2nd, and E must be 7th or 8th respectively.

Clue: "H is sixth to the right of C."

This means there are 5 people between C and H.

- Position of C must be 1st or 2nd, and H must be 7th or 8th respectively.

2. Combine the clues for the extreme ends:

Since A and C are both near the left end, and E and H are near the right end, let's test the two possibilities:

Case 1: If C is at position 1, then H is at position 7.

Then A must be at position 2, which makes E position 8.

Row layout for Case 1: [C, A, _, _, _, _, H, E]

Case 2: If A is at position 1, then E is at position 7.

Then C must be at position 2, which makes H position 8.

Row layout for Case 2: [A, C, _, _, _, _, E, H]

3. Analyze the remaining clues regarding G, F, and E:

Clue: "F is to the immediate right of G and neighbour of E."

This means G and F are together as (G, F), and F must be adjacent to E.

Let's evaluate Case 1: [C, A, _, _, _, _, H, E]

Here, E is at position 8. Since F is a neighbor of E, F must be at position 7. But H is at position 7 in Case 1! Thus, Case 1 is invalid.

Let's evaluate Case 2: [A, C, _, _, _, _, E, H]

Here, E is at position 7. F is a neighbor of E, so F can be at position 6. Since F is to the immediate right of G, G must be at position 5.

Now our row looks like: [A, C, _, _, G, F, E, H]

4. Place the remaining people (B and D):

The empty positions left are 3 and 4.

Clue: "B is not neighbour of G."

G is at position 5, so position 4 (adjacent to G) cannot be B. Therefore, D must be at position 4, and B must be at position 3.

Final Seating Arrangement (from left to right, 1 to 8):

1. A

2. C

3. B

4. D

5. G

6. F

7. E

8. H

5. Verification of the options:

- "C is to the immediate left of A." (Incorrect, C is to the immediate right of A)

- "D is immediate neighbour of B and F." (Incorrect, D is neighbor of B and G)

- "G is to the immediate right of D." (Correct, D is at position 4 and G is at position 5 directly to the right of D)

- "A and E are at the extreme ends." (Incorrect, A and H are at the extreme ends)

Thus, the correct statement is G is to the immediate right of D.