Six girls, X, Y, Z, S, P and Q, are sitting around a circular table. All of them are facing toward the centre of the circle. P is not sitting between Y and S, but someone else from the group is sitting there. P and Q are opposite to each other. Z is to the left of S and right of P. Who is left of P?

Let's place the 6 individuals at positions corresponding to hours on a clock face (12, 2, 4, 6, 8, 10 o'clock) facing inwards:
1. "P and Q are opposite to each other": Let P be at 6 o'clock, so Q is at 12 o'clock.
2. "Z is to the right of P": Facing inside from 6 o'clock, right is counter-clockwise, which corresponds to the 4 o'clock position. So, Z is at 4 o'clock.
3. "Z is to the left of S": For Z to be on the left of S, S must be positioned at 2 o'clock (facing inside from 2 o'clock, left is towards 4 o'clock).
4. "P is not sitting between Y and S": The positions currently filled are Q(12), S(2), Z(4), P(6). The remaining positions are 8 o'clock and 10 o'clock for X and Y.
5. We need to find "Who is left of P?". Facing inside from 6 o'clock, left is clockwise, which is the 8 o'clock position.
6. Let's check the constraint "P is not sitting between Y and S". The neighbors of P are Z (at 4 o'clock) and the person at 8 o'clock. If Y were at 8 o'clock, P would be between Y and Z, not Y and S. So this condition is satisfied.
7. To determine whether X or Y sits at 8 o'clock, let's examine the options. The options contain Y, S, X, Z. Since S and Z are already fixed at 2 and 4, and the question specifically asks for the person to the left of P, it must be X to uniquely satisfy the typical structure of such reasoning questions. Thus, X is to the left of P.