Assume that 40% of a country's population has had Covid and that 55% of the country's population has been vaccinated. There is some overlap between the two groups, and 25% of the country's population has both had Covid and has also been vaccinated. Either having Covid or being vaccinated gives some protection against getting Covid. Based on these assumptions, if you choose a resident of this country at random what is the probability that the person has either had Covid or has been vaccinated and therefore has some protection against Covid?