The first year you obtain your Professional Engineer seal, you design and observe construction of 3 small roadways with culverts, each of which is in a different area of the country. All of these roads are designed to pass a 50-year storm since they are not major roads where loss of life or damage to property is likely if they are flooded. After that first year, you never design another culvert for the rest of your career since you move into management.
What is the probability that at least one of those 3 roads will be overtopped in one given year. What is the probability for your anticipated 40-year career?