People are randomly selected one by one, and their eye-color recorded as blue" or not blue". Suppose that 20 percent of people have blue eyes. Let Xb be the number of people selected until the first person with blue eyes shows up, let Xn be the number of people selected until the first person with non-blue eyes shows up, and let X be the number of people select until the first person with a different eye color to the preceding people shows up. Determine E(Xb), E(Xn) and E(X).