Four buses carrying 142 high school students arrive to Montreal. The buses carry, respectively, 30, 50, 25, and 37 students. One of the 142 students...

Four buses carrying 142 high school students arrive to Montreal. The buses carry, respectively, 30, 50, 25, and 37 students. One of the 142 students is randomly selected. Let X denote the number of students that were on the bus carrying this randomly selected student. One of the four bus drivers is also randomly selected. Let Y denote the number of students on his bus. Compute the expectations and variances of X and Y: