Read the given instructions carefully and answer the related questions:

A certain number of persons are sitting in a row facing north.

Three persons sit between A and B. C sits second to the right of B. D sits fifth to the left of C. Two persons sit between D and E. The number of persons sit between D and C is one more than the number of persons sit between D and F. No one sits to the left of F. The position of A with respect to F is same as the position of C with respect to G. As many persons sit to the left of F as to the right of C.

How many persons sit between E and G?

Based on the instructions provided in the question, we can determine the step-by-step arrangement of the persons sitting in the row facing north:

Step 1: Understand the positions of B, C, and D
Let the positions in the row be numbered from left to right starting from 1.
Let the position of C be $x$.
According to the clue, "C sits second to the right of B". This means B is at position:
$x-2$
"D sits fifth to the left of C". This means D is at position:
$x-5$

Step 2: Determine the position of F
The number of persons sitting between D ($x-5$) and C ($x$) is 4 (which are the positions $x-4$, $x-3$, $x-2$, and $x-1$).
We are told: "The number of persons sitting between D and C is one more than the number of persons sitting between D and F."
Therefore, the number of persons sitting between D and F must be:
$4-1=3$
This means F is 4 positions away from D. Since "No one sits to the left of F", F must be to the left of D. Thus, the position of F is:
$(x-5)-4=x-9$

Step 3: Find the position of E
"Two persons sit between D and E". This means E is 3 positions away from D.
E can be at $(x-5)+3=x-2$ or $(x-5)-3=x-8$.
Since B is already at $x-2$, E must be at position:
$x-8$

Step 4: Analyze A and the total row size
"Three persons sit between A and B". B is at $x-2$.
If A is to the right of B, A would be at $x+2$. However, "As many persons sit to the left of F as to the right of C." Since F is at the extreme left (no one sits to the left of F), there are 0 persons to the left of F, which means there are 0 persons to the right of C. Hence, C ($x$) is the rightmost person, and no one can sit at $x+2$.
Therefore, A must be to the left of B at position:
$(x-2)-4=x-6$

Step 5: Set up the final layout and locate G
Letting the leftmost position of F ($x-9$) be 1, we get $x=10$. The arrangement of the 10 positions from 1 to 10 is:
1. F
2. E
3. [Person]
4. A
5. D
6. [Person]
7. [Person]
8. B
9. [Person]
10. C

We are given: "The position of A with respect to F is same as the position of C with respect to G."
A (position 4) is third to the right of F (position 1). Therefore, C (position 10) must be third to the right of G. This places G at position:
$10-3=7$

Step 6: Calculate the number of persons between E and G
E is at position 2 and G is at position 7.
The positions between E and G are 3, 4, 5, and 6.
Thus, there are exactly Four persons sitting between E and G.