Past perfect continuous - ongoing past action before a past point — IITM BS previous year questions

Past perfect continuous - ongoing past action before a past point is part of Past Tenses, Week 5 in English 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.