PERMUTATIONS AND COMBINATIONS | THE FACTORIAL, QUESTIONS, FACTORIAL PRINCIPLES OF COUNTING, FUNDAMENTAL PRINCIPAL OF COUNNTING, PERMUTATION | What is factorial Zero Factorial examples, (a)Compute (i) `(20!)/(18!)` (ii) `(10!)/(6!.4!)` (b)find n if `(n+2)! =2550*n!`, fundamental principle of multiplication, fundamental principle of addition, Difference and application of fundamental principals, There are 3 condidates for a Classical; 5 for a Mathematical and 4 for a Natural science scholarship.(i)In how many ways can these scholarship be awarded ? (ii) In how many ways one of these scholarships be awarded?, What is permutation ?, Notation + theorem :- Let r and n be the positive integers such that `1lerlen`. Then no. of all permutations of n distinct things taken r at a time is given by `(n)(n-1)(n-2).....(n-(r-1))`, Prove that `P(n,r)=nP_r=(n!)/((n-r)!`, The no. of all permutation of n distinct things taken all at a time is `n!`, Prove that 0! =1