60% of all students at a college still need to take another math class. If 4 students are randomly selected, find the probability that a. Exactly 2 of them need to take another math class. b. At most 2 of them need to take another math class. c. At least 2 of them need to take another math class. d. Between 2 and 3 (including 2 and 3) of them need to take another math class. Round all answers to 4 decimal places.