The probability that an individual without a college education earns more than $50,000 is 0.2, whereas the probability that a person with a B.S. or higher degree earns more than $50,000 is 0.6. The probability that a person chosen at random has a B.S. degree is 0.3. What is the probability that a person has at least a B.S. degree if it is known that he or she earns more than $50,000?