Calculating probability
A sample of 400 large companies showed that 120 of them offer free health fitness centers to their employees within the company premises. If one company is selected at random from this sample, what is the probability that this company offers a free health fitness center to it's employees within the premises? What is the probability that this company does not offer a free Health fitness center to it's employees within the company premises? Do these two probabilities add up to 1.0? If yes, why?