PERMUTATION AND COMBINATION
The theory of permutaions and combinations is central in problems of counting a large number of objects that are impossible to count manuallly. The theory of permutation and combinations enables us to count objects without listing or enumerating them . Permutation : Permutation refer to the number of different arrangements of given objects, when the order is important . i.e. A permutaion is an arrangement , in a definite order , of a number of objects , taken some or all at a time. Formula: The formula for permutation of n objects for r selection of objects is given by: P(n,r) = n!/(n-r)! For example, the number of ways 3rd and 4th position can be awarded to 10 members is given by: P(10, 2) = 10!/(10-2)! = 10!/8! = (10.9.8!)/8! = 10 x 9 = 90 Linear Permutation : 1. The number of permutation od n different objects taken r at a time when repetition of r object...