Who among A B C D and E does teach History? Statements I. 1 Each one of them teaches only one subject. B teaches Mathematics while E teaches Science. A or C soes not teach Geography. A or D does not teach English. II. C and E are teachers of English and Science respectively and A is the teacher of Mathematics.

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.