सिद्ध कीजिए कि `""^(n)P_(r) = n.""^(n-1)P_(r-1)`

What is ""^(n-1)P_(r )+ ""^(n-1)P_(r-1) ?

If ""^(n)P_(r)=k xx ""^(n-1)P_(r-1) what is k:

If show that "^(n-1)P_r = (n-r).^(n-1)P_(r-1)

Prove that: ""^(n-1)P_r=(n-r)* ""^(n-1)P_(r-1)

Prove that: (i) ""^(n)P_(n)=""^(n)P_(n-1) " (ii) "^(n)P_(r)=n* ""^(n-1)P_(r-1) " (iii) "^(n-1)P_(r)+r* ""^(n-1)P_(r-1)=""^(n)P_(r)

(n-1)P_(r)+r.(n-1)P_(n-1) is equal to

Prove ""^(n)P_(r)=""^(n-1)P_(r) +r. ""^(n-1)P_(r-1)

11. Prove that nP_(r)=n(n-1)P_(r-1)