Problem 20
Final exams took place over a span of 18 days. Each of the 18 days had a morning and an afternoon session. A girl had to take 6 exams total. She looked at the exam schedule and found she had two days in which she had to take two finals each, one in the morning and one in the afternoon. She thought to herself, "What are the chances of that happening?" What is the probability that she would have 6 exams set on just 4 days?
Show your work.
