Help I need understanding with the following two questions

Let A be the event that a student is enrolled in an accounting course, and let S be the event that a student is enrolled in a statistics course. It is known that 30% of all students are enrolled in an accounting course and 40% of all students are enrolled in statistics. Included in these numbers are 15% who are enrolled in both statistics and accounting; Given the prior knowledge that a student is enrolled in accounting, what is the probability that this student is also enrolled in statistics? Select one: '3 a. 0.3?5 b- 0.15 '3 c. 0.50 C) 0.?5 Suppose that past history shows that 20% of Cityrail trains are late. A sample of 12 trains is selected for an experiment. The probability that exactly 1 train is late is Select one: O a. 0.206 O b. 0.234 O c. 0.069 O d. 0.6