Perpendicular lines - slopes are negative reciprocals (m1 * m2 = -1) — IITM BS previous year questions

Perpendicular lines - slopes are negative reciprocals (m1 * m2 = -1) is part of Parallel and Perpendicular Lines, Week 2 in Mathematics 1. Prasnya files every IIT Madras BS previous year question from this subtopic here, each one with a worked explanation. Take the whole set as a timed mock and you get accuracy, pacing and per-question analysis back.