Among P Q R S and T sitting in a straight line facing North who sits exactly in the middle of the line ? I. P sits third to left of S. T is an immediate neighbour of P as well as R. II. T sits second to left of S. Q is not an immediate neighbour of either T or S.

Data sufficiency questions are designed to check your ability to analyse & categorise information based on underlying concepts rather than calculations. So you should try to observe -  analyse and to find linkages between various statements rather soing lengthy calculations.