Final Answer:
Rosalyn can pick the students in 380 different ways.
Step-by-step explanation:
When Rosalyn picks the first student, she has 20 choices. After she picks the first student, she only has 19 students left to choose from, so there are 19 different ways to pick the second student. Therefore, the total number of ways to pick 2 students is 20 x 19 = 380.