need help with the following question!

Problem 5) (2 points) A class of 60 students is driven to a mathematics exhibition, at the Fields Institute, in three buses. There are 30 students in one of the buses, 18 in the second bus, and 12 in the third bus. When the buses arrive at the exhibition, one of the 60 students is chosen randomly. Whoever is chosen wins a mathematics textbook, along with everyone else in the same bus they arrived in. How many textbooks can the Fields Institute expect to give away