Who among P Q R S and T is the heaviest ? I. Q is heavier than R and T but lighter than only S II. R is third from the top when they are arranged in sescending order of their weight and is heavier than T andd P.

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.