Six friends P, Q, R, S, T, U sit on a bench. P is next to Q, U is next to T, and R is between S and U. If T is not at either end, who occupies one of the ends?

1. Sequence R between S and U means S-R-U or U-R-S triplet exists. 2. U-T adjacency extends to S-R-U-T or T-U-R-S blocks. 3. P-Q must be adjacent and outside this 4-block. 4. Since T is not at an end, the 4-block sits in the middle and PQ flanks one end; P (or Q) can be at the end. Among options, P is at an end. _Source: ICAI BoS Foundation Paper 3, Ch 11 'Seating', p.4_