The value of $$\frac{1}{2 !}+\frac{2}{3 !}+\ldots+\frac{99}{100 !}$$ is equal to

If the sum of 12th and 22nd terms of an AP is 100, then the sum of the first 33 terms of an $$\mathrm{AP}$$ is

If three numbers $$a, b, c$$ constitute both an A.P and G.P, then

Le $$x$$ be the arithmetic mean and $$y, z$$ be the two geometric means between any two positive numbers, then $$\frac{y^3+z^3}{x y z}=$$ -----------