Determinant as a test for singularity and invertibility — IITM BS previous year questions

Determinant as a test for singularity and invertibility is part of Determinants - Basics, Week 1 in Mathematics 2. 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.