1it means dat the question is incomplete, hena??
Do u want d proof for nPr= n!/(n-r)!???
8 Answers
62this is not very tough...
Easiest without thinking: Try with induction...
1
3nishant sir any other method not by taking examples, and mathematical induction...
62yup the simple method....
1st place can be filled in n ways
2nd can be in n-1 ways
3rd in n-2 ways
rth in n+1-r ways
Each is independent of all the previous ones...
Hence total number of ways is
n.(n-1)....(n+1-r) which is denoted by definition as nPr