Suppose that a and b are independent events with p(a) = 0.3 and p(b) = 0.45. what is the probability that at least one of the two events occurs?

Identify all the cases where non-probability sampling is used when attempting to study the characteristics of a large city. studies on every subject in the population divide a population in groups and obtain a sample studies with a limited amount of time demonstrate existing traits in a population studies with the nth person selected