This is the book, in which the subject matter is dealt from elementary to the advance level in a unique manner. Three outstanding features can be claimed for the book viz. (i) style; the student, while going through the pages would feel as if he is attending a class room. (ii) language: that an average student can follow and (iii) approach: it takes the student from ''known to unknown'' and ''simple to complex.'' The book is reader friendly, thought provoking and stimulating. It helps in clearing cobwebs of the mind. The style is lucid and un-adulterated. Unnecessary mathematics has been avoided.