Explanation:

- B sits at the extreme right end of the row.

- G sits second to the left of B, so the arrangement is _ _ _ _ _ G B.

- E sits exactly between G and B, making the arrangement _ _ _ E G B.

- D is third to the left of C. C therefore sits at position 6 or 7 since only these allow space for D based on E and G's position.

- If C is at position 7 (_ _ _ E G C B), D would be off the extreme left. Hence, C cannot be at 7.

- So, C is at position 6 (_ _ _ E G C B), making D at position 3 (_ D _ E G C B).

- A sits second to the right of D, thus A is at position 5 (_ D _ E A C B).

- F must occupy one of the remaining positions and has two persons between F and G, hence F is at position 2 ( _ D F E A C B).

- Arrangement completion: A sits at the third position from left (before A, D and F are sitting).

Therefore, the final order is: A D F E G C B.

- ? Two persons (G and C) sit between B and C.