Seven persons — A, B, C, D, E, F and G — are attending an event one after another, but not necessarily in the same order. G attends the event three persons after C. B attends the event immediately before C. Only one person attends the event between B and E. D attends the event four persons after E but before A. Three persons attend event between A and F.

Who attends the event in the last position?

The correct option is G.

Let's solve the puzzle step-by-step to determine the position of each of the seven persons (positions 1 to 7, where position 1 attends first and position 7 attends last).

Step 1: Understand the given clues

1. There are 7 positions in total: 1, 2, 3, 4, 5, 6, 7.
2. "G attends the event three persons after C" means there are 2 persons between C and G: $\text{C},\text{\_},\text{\_},\text{G}$ (i.e., Position of G = Position of C + 3).
3. "B attends the event immediately before C" means B and C form the pair $\text{B}\text{C}$.
4. "Only one person attends the event between B and E" means E is placed 2 positions away from B (either before or after).
5. "D attends the event four persons after E but before A" means Position of D = Position of E + 4, and D attends before A.
6. "Three persons attend event between A and F" means there are 3 persons between A and F.

Step 2: Determine positions using clues about E, D, and A

Since D attends 4 persons after E, the distance between E and D is 4 positions (i.e., $\text{E},\text{\_},\text{\_},\text{\_},\text{D}$).
Also, D attends before A, so A must be placed at a position after D.
Since there are only 7 positions total, the only possible positions for E, D, and A are:

- Position of E = 1
- Position of D = 1 + 4 = 5
- Position of A = 6 (since D is before A, and A must leave room for other constraints).

Step 3: Determine the position of F

Three persons attend between A and F.
Since Position of A = 6, counting 3 positions before A gives:
Position of F = 6 - 4 = 2.
So, F is at Position 2.

Step 4: Determine the positions of B, C, and G

We know:
- B is immediately before C ($\text{B}\text{C}$).
- One person attends between B and E. Since E is at Position 1, B must be at Position 3.
- If B is at Position 3, then C must be at Position 4.
- G attends 3 persons after C, so Position of G = 4 + 3 = 7.

Step 5: Final order of attendance

Position 1: E
Position 2: F
Position 3: B
Position 4: C
Position 5: D
Position 6: A
Position 7: G

Therefore, G attends the event in the last position (Position 7).