DIRECTIONS for questions: Read the information given below and answer the question that follows.

A round table has seven chairs around it. The chairs are numbered 1 through 7 in a clockwise direction. Four friends, Aslam, Bashir, Chhavi, and Davies, sit on four of the chairs. In the starting position, Aslam and Chhavi are sitting next to each other, while for Bashir as well as Davies, there are empty chairs on either side of the chairs that are sitting on. The friends take turns moving either clockwise or counter clockwise from their chair.

The friend who has to move in a turn occupies the first empty chair in whichever direction (s)he chooses to move. Aslam moves first (Turn 1), followed by Bashir, Chhavi, and Davies (Turns 2, 3, and 4, respectively). Then Aslam moves again followed by Bashir, and Chhavi (Turns 5, 6, and 7, respectively).

The following information is known.

1. The four friends occupy adjacent chairs only at the end of Turn 2 and Turn 6.

2. Davies occupies Chair 2 after Turn 1 and Chair 4 after Turn 5, and Chhavi occupies Chair 7 after Turn 2

Who sits on the chair numbered 4 at the end of Turn 3?

The correct answer is No one.

Let's deduce the initial seating arrangement of the four friends around the 7 chairs (numbered 1 to 7 in a clockwise direction). We are given that Aslam and Chhavi sit next to each other, and both Bashir and Davies must have empty chairs on either side of them.

First, we know from the given conditions that Davies occupies Chair 2 after Turn 1. Since only Aslam moves in Turn 1, Davies has not moved yet and must have started in Chair 2. For Davies to have empty chairs on either side of him, Chairs 1 and 3 must be empty.
Next, we know Chhavi occupies Chair 7 after Turn 2. Because she does not move until Turn 3, she must have started in Chair 7. We are also told that Aslam and Chhavi are seated next to each other. With Chair 1 being empty, Aslam must be seated in Chair 6.
Finally, Bashir must also have empty chairs on both sides. The only remaining unoccupied chairs at this point are Chairs 4 and 5. If Bashir sits in Chair 5, he would be directly next to Aslam (in Chair 6), which violates the condition. Therefore, Bashir must start in Chair 4, leaving Chairs 3 and 5 empty. This gives us our starting arrangement:

Chair 1: Empty
Chair 2: Davies
Chair 3: Empty
Chair 4: Bashir
Chair 5: Empty
Chair 6: Aslam
Chair 7: Chhavi

Turn 1: Aslam moves from Chair 6. He can occupy the first empty chair in either direction. Clockwise, the first empty chair is Chair 1. Counter-clockwise, the first empty chair is Chair 5. Let's determine his direction. If Aslam moves to Chair 5, the occupied chairs become 2, 4, 5, and 7. In Turn 2, Bashir would move from Chair 4. We are told that at the end of Turn 2, the four friends occupy adjacent chairs (a contiguous block of 4). If Aslam is at Chair 5, Bashir moving to either Chair 3 or 6 will fail to form a contiguous block of 4. Therefore, Aslam must have moved clockwise to Chair 1. The occupied chairs are now 1 (Aslam), 2 (Davies), 4 (Bashir), and 7 (Chhavi).

Turn 2: Bashir moves from Chair 4. To form the required contiguous block of four adjacent chairs by the end of this turn, he must move counter-clockwise to the first empty chair, which is Chair 3. Now, Chairs 7, 1, 2, and 3 are occupied by Chhavi, Aslam, Davies, and Bashir respectively, fulfilling the adjacency condition perfectly.

Turn 3: Chhavi moves from Chair 7. The currently empty chairs are 4, 5, and 6. She can either move clockwise to the first empty chair (Chair 4) or counter-clockwise to the first empty chair (Chair 6). To figure out her move, we look ahead. We know that Davies occupies Chair 4 after Turn 5. Since Davies only moves during Turn 4, he must land on Chair 4 during his turn. If Chhavi were to move to Chair 4 now, it would be occupied, preventing Davies from moving there in Turn 4. Therefore, Chhavi cannot move to Chair 4; she must move counter-clockwise to Chair 6.

At the end of Turn 3, the exact arrangement of the round table is:
Chair 1: Aslam
Chair 2: Davies
Chair 3: Bashir
Chair 4: Empty
Chair 5: Empty
Chair 6: Chhavi
Chair 7: Empty

Therefore, we can conclusively state that at the end of Turn 3, the chair numbered 4 is occupied by no one.