From $10$ students, a committee of $6$ is to be arranged which contain a President, a Vice President and a secretary. In how many ways this can be arranged? When we try to solve these problems practically, it will be very difficult and time consuming. Hence we use the method of permutation and combinations to make these arrangements. In this section let us see about the meaning of the terms Permutations and Combinations and the method of evaluating them using appropriate formulae.