If` 1/3!+1/4!=n/5!`.Find the value of `n`.

Let A_1,A_2,....A_n be the vertices of an n-sided regular polygon such that , 1/(A_1A_2)=1/(A_1A_3)+1/(A_1A_4) . Find the value of n.

The mid-point of the segment joining (3m, 6) and (-4, 3n) is (1, 2m, -1). Find the values of m and n.

There are 'n' A.M.'s between 2 and 41. The ratio of 4th and (n - 1)th mean is 2 : 5, find the value of n.

There are n A.M. s between 3 and 29 such that 6th mean : (n - 1) th mean ::3 :5 then find the value of n.

(i) If (n!)/(2.(n-2)!): (n!)/(4!.(n-4)!) = 2:1 , find the valye of n. (ii) If ((2n)!)/(3!(2n-3)!): (n!)/(2!(n-2)!) = 44:3 , then find the value of n.

If "^(2n+1)P_(n-1):^(2n-1)P_n=3:5, then find the value of n .

If .^(n)C_(r-1): .^(n)C_(r): .^(n)C_(r+1)=3:4:5 , find the values of n and r.

If 25^(n-1) + 100 = 5^ (2n-1) , find the value of n :

If n in NN , then find the value of i^n+i^(n+1)+i^(n+2)+i^(n+3) .