2. Five students are to be selected from 6 grade 9 students, 10 grade 10 students, 8 grade 11 students, and 9 grade 12 students. Determine the probabilities of the following events. Give your answers as a fraction, decimal and percent. a. The students are all from the same grade b. There are no grade 9 students selected c. There are exactly three or four grade 12 students d. There is at least one grade 11 student chosen