Six members of a panel are sitting in a row. X is to the left of Q but to the right of P. Y is to the right of Q but to the left of Z, and Z is to the left of R. Which two members occupy the extreme left and extreme right positions in the row?

Introduction / Context:
This is a linear seating arrangement question, a staple of logical reasoning and aptitude tests. You are given relational information about where certain people sit relative to each other in a row. From these clues, you must deduce the complete order and then answer a specific query about who sits at the extremes. Such questions assess your ability to convert verbal conditions into a clear mental or written diagram.

Given Data / Assumptions:
There are six members: P, Q, R, X, Y and Z, all sitting in a single row. The conditions given are: X is to the left of Q but to the right of P. Y is to the right of Q but to the left of Z. Z is to the left of R. We assume all six members occupy distinct consecutive positions with no empty chairs between them. The question asks which two members are at the two extreme ends, that is, the leftmost and rightmost positions.

Concept / Approach:
The best approach is to interpret each statement as a partial ordering and then combine them to form one complete left to right sequence. When we say A is to the left of B, we infer that A is earlier in the row than B. Constraints like A is to the right of B and to the left of C place A between B and C. By chaining these constraints together carefully, we obtain a unique or at least consistent arrangement. From this arrangement, the extremes become obvious.

Step-by-Step Solution:
From X is to the left of Q but to the right of P, we know P, X, Q appear in that order: P ... X ... Q. From Y is to the right of Q but to the left of Z, we place Y and Z to the right of Q while keeping the order Q ... Y ... Z. From Z is to the left of R, we extend the chain to Z ... R. Combining all relationships gives one continuous ordering: P is left of X, X is left of Q, Q is left of Y, Y is left of Z and Z is left of R. Therefore the full left to right arrangement is P, X, Q, Y, Z, R. The extremes of the row are P at the left end and R at the right end.

Verification / Alternative check:
To verify, check each given condition against the final arrangement P X Q Y Z R. X is indeed to the left of Q and to the right of P, so the first statement holds. Y is to the right of Q and to the left of Z, matching the second condition. Z is to the left of R, satisfying the third statement. All three constraints are consistent with the derived order, and no member is left unplaced. Since all conditions are respected simultaneously, the arrangement is valid and unique for the purposes of this question. The extremes P and R are therefore confirmed.

Why Other Options Are Wrong:
Q and Z are in the middle of the row and do not occupy the ends. X and Z are also both internal members, with P to the left of X and R to the right of Z. Q and Y are the third and fourth members from the left, so they clearly are not extremes. P and Y places Y as an extreme, but Y actually has Z and R to its right in the correct arrangement. Only P and R match the leftmost and rightmost positions in the valid seating order, making P and R the only correct pair.

Common Pitfalls:
A frequent mistake is to misinterpret phrases like to the right of and treat them as immediate neighbours instead of just positional relations. Another pitfall is to draw several partial chains but fail to join them correctly, leading to contradictory placements. Some candidates also ignore one of the conditions after partially fixing the order and end up with an arrangement that violates a later statement. To avoid these issues, always write the chain step by step, check each new relation against what you already have and ensure that all six names are placed. Only then should you answer questions about extremes or relative order.

Final Answer:
In the panel seating arrangement, the two members at the extremes are P and R.