Given Equation :

To Find : Value of n

Formula :

By given equation,

By using above formula,

Cancelling terms (n - 2)! , (2!), (2n - 3)! & n, we get,

….. taking 2 common from the term (2n - 2)

∴ (2n - 1) = 11

∴n = 6

Conclusion : Value of n is 6.