n mole each of `H_(2)O(g),H_(2)(g) "and" O_(2)(g)` are mixed at a suitable high temperature to attain the equilibrium `2H_(2)O(g)hArr2H_(2)(g)+O_(2)(g)`. If `y` and mole of `H_(2)O(g)` are the dissociated and the total pressure maintained is `P`, calculate the `K_(P)`.