135 Studying exam questions. A college professor hands out a list of 10 questions, 5 of which will appear on the final examination for the course. One of the students taking the course is pressed for time and can prepare for only 7 of the 10 questions on the list. Suppose the professor chooses the 5 questions at random from the 10.

a. What is the probability that the student will be prepared for all 5 questions that appear on the final examination?

b. What is the probability that the student will be prepared for fewer than 3 questions?

c. What is the probability that the student will be prepared for exactly 4 questions?