Question

Four buses carrying 154 high school students arrive to Montreal. The buses carry, respectively, 40, 45, 25, and 44 students. One of the studetns is randomly selected. Let X denote the number of students that were on the bus carrying this randomly selected student. One of the 4 bus drivers is also randomly selected. Let Y denote the number of students on his bus. Compute the expectations of X and Y.
E(X) = ?
E(Y) = ?