" R) If "^(n_(P_(4)))=1680" the "n=

If ""^(n)P_(4)=1680, find n.

If ""^(n)P_(r)=110 , then n + r =

If P(n,4)=1680 then find n=

If ""^(n)P_(r)=3024 then (n,r) is

If .^(n)P_(r)=3024 then (n,r) is

If a,b,c are the values of n where ""^(n)P _(7) = 42 ""^(n)P_(5) ,""^(n)P_(4) = 1680 , ""^(n) P_(3) =1320 respectively then the ascending order of a,b,c is

Find n and r if ""^nP_r=1680,""^nC_r=70.

((n),(r)) = (""^(n)P_(r))/(K), then K = ......