Find the value of n such that
`""^(n)P_(5)=42""^(n)P_(3), n gt 4`

Find the value of n such that (""^(n)P_(4))/(""^(n-1)P_(4))=(5)/(3), n gt 4

If .^(n)P_(5)=20 .^(n)P_(3) , find the value of n.

Find n if ""^(n-1)P_(3) : ""^(n)P_(4)=1:9 .

If ""^(n) P_(4)=20(""^(n)P_(2)) then find the value of n.

If ""^(n)P_(4) = 24^(n)C_(5) then the value of n=

Find 'n' if (""^(n)P_(4))/(""^(n-1)P_(4))= (5/3) ?

Prove that .^(n-1)C_(3)+.^(n-1)C_(4) gt .^(n)C_(3) if n gt 7 .

Consider a polygon of sides 'n' which satisfies the equation 3*^(n)P_(4)=^(n-1)P_(5) . Q. Number of quadrilaterals thatn can be formed using the vertices of a polygon of sides 'n' if exactly 1 side of the quadrilateral in common with side of the n-gon, is

Find the negative terms of the sequence X_(n)=(.^(n+4)P_(4))/(P_(n+2))-(143)/(4P_(n))

Prove that 1* ""^(1)P_(1)+2* ""^(2)P_(2)+3* ""^(3)P_(3) + … +n* ""^(n)P_(n)=""^(n+1)P_(n+1)-1