P, Q, R, S and T sit in a straight line facing north. P sits next to S but not to T. Q sits next to R, who sits at the extreme left corner. T does not sit next to Q. Who sits to the left of S?

P sits to the left of S.

R is at the extreme left (seat 1) and Q, next to R, takes seat 2.

T must not be next to Q, so T cannot take seat 3.

Putting P at seat 3 and S at seat 4 keeps P beside S and away from T.

T then takes seat 5, giving R, Q, P, S, T, with P not next to T.

The seat left of S (seat 3) holds P.