Well, we can break this down into a few steps. First off, if we split these 600 students up into groups of 10, we're doing 600/10 groups, or 60 groups total. Then, if we randomly pick one student from each group, in total, we're surveying 60 students.
This is also an example of "stratified sampling". But that part's more of just knowing the vocabulary for statistics. Hope this helps!