To find the number of students in each bus, we first need to find the number of students who actually went on the 9 buses. Because there were total 472 students and 4 went on cars, then there were a total of 472-4=468 students who went on the 9 buses. If 468 went on the 9 buses, then 468/9=52 students went on each bus. This can be represented by the following equation:
472-4=9s
OR
472=9s+4
Or another equivalent of this equation because we had to first minus 4 from 472 to find the total number of bus students and then divide by 9 to find s, the number of students per bus. However this equation doesn't seem to be part of the options so I don't really know what's going on with that.
