Among 500 freshmen pursuing a business degree at a university, 344 are enrolled in an economics course, 209 are enrolled in a mathematics course, and 124 are enrolled in both an economics and a mathematics course. What is the probability that a freshman selected at random from this group is enrolled in each of the following? (Enter your answers to three decimal places.) (a) an economics and/or a mathematics course Incorrect: Your answer is incorrect. (b) exactly one of these two courses Incorrect: Your answer is incorrect. (c) neither an economics course nor a mathematics course Incorrect: Your answer is incorrect.