P, Q, R, S, T and U are sitting around a circular table facing the centre. Only one person sits between T and R. Only one person sits between R and U. Only two people sit between U and Q. S sits to the immediate left of T. Who sits second to the left of P?

To find out who sits second to the left of P, let us analyze the seating arrangement step-by-step based on the given clues.

We have 6 people: P, Q, R, S, T, and U sitting around a circular table facing the centre.

Step 1: Position T and S.
According to the clue, "S sits to the immediate left of T".
Let us assign a position to T. If T is at position 1 (assuming positions 1 to 6 go clockwise), since they are facing the centre, the immediate left of T corresponds to position 2 (going clockwise).
Therefore, T is at position 1 and S is at position 2.

Step 2: Position R.
The clue states: "Only one person sits between T and R".
From T (position 1), R can be either at position 3 (with S at position 2 in between) or at position 5 (with position 6 in between).
Since S is already at position 2, the only person between T and R must be S. Therefore, R must be placed at position 3.

Step 3: Position U.
The clue states: "Only one person sits between R and U".
From R (position 3), the positions that are "one person away" are position 1 (with position 2 in between) and position 5 (with position 4 in between).
Since T is already at position 1, U must be at position 5. The person between R (position 3) and U (position 5) will be at position 4.

Step 4: Position Q.
The clue states: "Only two people sit between U and Q".
In a 6-person circular table, sitting "only two people between U and Q" means U and Q are sitting directly opposite to each other.
Since U is at position 5, the position opposite to it is position 2 (which is occupied by S), or we can count 3 places in either direction:
5 - 3 = 2, and 5 + 3 = 8 (which is position 2 in a modulo 6 system).
Wait, let's re-verify the counting:
If we have positions 1, 2, 3, 4, 5, 6 around a circle:
Opposite of 1 is 4.
Opposite of 2 is 5.
Opposite of 3 is 6.
Here, S is at 2, and U is at 5, which means S and U are opposite each other (two people sit between them: 3, 4 on one side, and 6, 1 on the other side).
Let us re-evaluate the placement of R.
If T is at position 1, S is at position 2 (immediate left of T, going clockwise).
"Only one person sits between T and R."
R could be at position 5 (going counter-clockwise, with position 6 in between). Let's test this alternative layout:
- T is at 1.
- S is at 2.
- R is at 5 (so position 6 is between T and R).
- "Only one person sits between R and U."
Since R is at 5, U could be at 3 (with 4 in between) or at 1 (which is occupied by T). So U must be at 3.
- "Only two people sit between U and Q."
This means Q must be opposite U. Since U is at 3, the opposite position is 6. So Q is at 6.
- This leaves only position 4 empty, so P must be at position 4.

Let's check all the conditions with this arrangement:
1. Six people: P (4), Q (6), R (5), S (2), T (1), U (3).
2. "Only one person sits between T (1) and R (5)": Yes, Q (6) sits between them.
3. "Only one person sits between R (5) and U (3)": Yes, P (4) sits between them.
4. "Only two people sit between U (3) and Q (6)": Yes, the two people are P (4) and R (5) on one side, and S (2) and T (1) on the other side.
5. "S sits to the immediate left of T": Since they face the centre, clockwise is left. T is at 1, immediate left (clockwise) is 2, where S is. This is correct.

Step 5: Find who sits second to the left of P.
P is at position 4.
Facing the centre, the direction to the left is clockwise.
- The immediate left (first to the left) of P (4) is U (3).
- The second to the left of P (4) is S (2). But wait, let's trace the positions carefully.
Let's draw the circle clockwise:
1: T
2: S
3: U
4: P
5: R
6: Q
Let's check the left direction. For a person facing the centre:
At position 4 (bottom, if 1 is top, 4 is bottom): facing up (centre).
Left of P is towards the right side of the circle, which is position 5 (counter-clockwise? No, if you face the centre from the bottom (position 4), your left hand points to the right, which is position 3 (counter-clockwise if 1 is 12 o'clock, 3 is 3 o'clock, 4 is 6 o'clock, 5 is 8 o'clock etc. Let's map to clock positions:)
Let's use standard clock positions:
12 o'clock = T (1)
10 o'clock = Q (6)
8 o'clock = R (5)
6 o'clock = P (4)
4 o'clock = U (3)
2 o'clock = S (2)
Let's trace this:
- S (2 o'clock) is to the immediate left of T (12 o'clock). Facing centre from 12 o'clock, left is towards 2 o'clock. Correct.
- One person sits between T (12 o'clock) and R (8 o'clock): Yes, Q (10 o'clock) is between them.
- One person sits between R (8 o'clock) and U (4 o'clock): Yes, P (6 o'clock) is between them.
- Two people sit between U (4 o'clock) and Q (10 o'clock): Yes, they are opposite each other.
- S (2 o'clock) sits to the immediate left of T (12 o'clock): Correct.
Now, who sits second to the left of P (6 o'clock)?
Facing the centre from 6 o'clock (looking north):
- Immediate left (west/left) is towards 4 o'clock, which is U.
- Second to the left is towards 2 o'clock, which is S. But wait, if you look north from 6 o'clock, your left is west (towards 8 o'clock).
Let's verify: at 6 o'clock, facing north (centre):
- Right hand points to 4 o'clock (East).
- Left hand points to 8 o'clock (West).
So immediate left of P is R (8 o'clock).
Second to the left of P is Q (10 o'clock).
Therefore, Q sits second to the left of P.