Application of Fermat's Theorem

A simple Application of Fermat's Theorem to find the remainder of a large number upon dividing by some positive integer, Click here to download

Pigeon Hole Principle and Divisibility

Here is a good problem Pigeon Hole Principle and Divisibility of integers. These type of problems are important for  Olympiads, Indian Statistical Institute (ISI) and  Chennai Mathematical Institute (CMI) .
Get the pdf file here. Please leave your comment.

Problem on Functional Equation

Here is a good problem of functional Equation where the form of the function is unknown and you have to find the value of the derivative of the function at some given point. What will be given is a equation which the function is satisfying along with some other values of the function or the derivatives. These type of problems are important for Indian Statistical Institute (ISI) , Chennai Mathematical Institute (CMI) or even IIT.
Here is the link to the problem.