This is a classic math problem book for students who are about to partake in mathematics in the ISI entrance exam. 

PS:- the solutions are available here. 

This is one of my favorite books in the whole world. I learnt continuum mechanics from Prof. Jog himself, and this book was a great source. 

The author has a very intuitive way of explaining differential geometry. Tensor algebra does not get easier than this. The chapters on Tensor Algebra were turned into a series of lectures on youtube. Pavel Grinfeld has a website called Lemma which is definitely worth checking out for math enthusiasts.