If `frac{(n-1)!}{(n-4)!}`: `frac{n!}{(n-4)!}` = 1:9, find the value of n

If (n!)/((2!)xx(n-2)!): (n!)/((4!)xx(n-4)!)=2:1 , find the value of n.

If n! = ((n + 4)!)/((n + 1)!) , then the value of n is :

If (n!)/(2!(n-2!)) and (n!)/(4!(n-4!)) are in the ratio 2:1, find the value of n.

13. If P(n-1,2):P(n,4)=1:9, find n

If 16^(n+1) = 64 xx 4^(-n) , the value of n is

If P(n-1,3):P(n,4)=1:9 find n

If 2^(n-7) xx 5^(n-4)=1250, find the value of n. Hint: 2^(n-4) xx 2^(-3) xx 5^(n-1)=1250 implies frac(2^(n-4) xx 5^(n-4))(2^(3))= 1250 implies (2 xx 5)^(n-4)=(10)^(4).