Seema goes 30 km towards North from a fixed point, then after turning to her right she goes 15 km. After this she turns
Mechanistically, quantitative reasoning involves ratio, percentage and series logic determine correct calculation. This validates 15 km East because it meets mathematical and logical criteria, a pattern repeatedly demonstrated in aptitude and reasoning research.
Ref: Wren and Martin, High School English Grammar and Composition, Revised Edition, Chapter 12, discusses vocabulary and comprehension providing guidance for verbal aptitude and logical inference assessment.