In order to accommodate (or provide space for) all students, with the maximum students per class being 15, there needs to be at least enough for 112. A way to figure this out is 112 / 15 (the total amount of people signed up divided by the amount per class). The quotient is 7.466..., which does not work since you cannot have a 0.466... of a human in a class. This means you must round to the nearest whole number. If there were more students it could accommodate 8 more being that 15 * 8 is 120, but in this case there are only 112.
