Problem 3 (10 points). First write the argument in symbolic form. Then identify the rule of inference that makes the argument valid. (a) If it snows today, the university will close. The university is not closed today. Therefore, it did not snow today. (b) Kangaroos live in Australia and are marsupials. Therefore, kangaroos are marsupials 2 e) Steve will work at a computer company this summer. Therefore, this summer Steve will work at a computer company or he will be a beach bum