If `.^(n)P_(r)=x.^(n)C_(r)` x=

If .^(n)P_(r)=.^(n)P_(r+1) and .^(n)C_(r)=.^(n)C_(r-1) , find n and r.

If .^(n)P_(r)=24.^(n)C_(r) then r= _______

If .^(n)P_(r)=840,.^(n)C_(r)=35, then find n=

What is the relation between .^(n)P_(r) and .^(n)C_(r) ?

If ^(n)P_(r)=^(n)P_(r+1) and ^(n)C_(r)=^(n)C_(r-1, then the ) value of n+r is.

If .^(n)P_(r)=720 and .^(n)C_(r)=120 then find the value of r.

If ""^(n)P_(r) = ""^(n)P_(r+1) and ""^(n)C_(r) = ""^(n) C_(r-1) then the value of r is equal to

If .^(n)P_(r) =360 and .^(n)C_(r)=15 , then find the value of r.

If (1-x^(2))^(n)=sum_(r=0)^(n)a_(r)x^(r)(1-x)^(2n-r), then a_(r) is equal to ^(n)C_(r) b.^(n)C_(r)3^(r) c.^(2n)C_(r) d.^(n)C_(r)2^(r)

If (1+2x+x^(2))^(n)=sum_(r=0)^(2n)a_(r)x^(r), then a=(^(n)C_(2))^(2) b.^(n)C_(r).^(n)C_(r+1) c.^(2n)C_(r) d.^(2n)C_(r+1)