You seem to be looking for a specific resource to help with IIT Mathematics problems. "Problems Plus in IIT Mathematics" by A. Das Gupta is a well-known book that provides additional practice problems for students preparing for the IIT JEE exams.
: Fora like Quora , Reddit (r/JEENEETards) , and specialized Telegram study groups frequently share handwritten solution PDFs created by top-ranking students. Key Features of Problems Plus in IIT Mathematics You seem to be looking for a specific