First, we know that the total number of students that attended the trip is 358 and 8 of those students traveled by car. To find out the number of students that traveled by bus, we need to subtract the number of students who travelled by car which is 8 from the total number of students. Thus, 358 students - 8 students equals to 350 students. Therefore, 350 students traveled by bus.
In order to find out how many students were on each bus, we will divide the number of students that traveled by bus, which is 350, by the total number of buses, which is 7.
We calculate 350 students / 7 buses and get the result of 50 students.
Therefore, each bus carried 50 students on the trip to the zoo.