Let Us C Solutions, by Yashwant Kanetkar, is one of the most sold books of programming in India and South Asian countries. It contains the concept of C and has great coverage of programming, algorithm, and Data Structures. I bring you the well-explained solutions of all the chapters in the book; let us C with a description of each solution in the comments wherever required. If any answer doesn't seem correct or incomplete, you can reach out to me, require more clarification and simplification, or have some syntax issue.
This book has been the first step in programming of many developers worldwide as C is still considered the first programming language to be learned in many institutions. This is because the author Yashwant Kanetkar has focused the book's content targeting newbies in programming and teaching, not just the language features but also basic technical terminologies of programming and computers.
It also walks you through setup the IDE for preparing your development environment.