Random Sampling: In this kind of sampling, elements are randomly chosen from a particular population. Every elements of the population carries the same probability in this case.
Systematic Sampling: Every k-Th element is taken for this kind of sampling.
Convenience Sampling: Here samples are chosen as per the accessibility.
Cluster Sampling: First the whole population is divided in some groups or cluster, then some groups are randomly selected.
Stratified Sampling: The whole population is being divided into groups as per some characteristic. Then from each group, one sample is to be chosen either randomly or using some other process.
Since, in the given question the students are chosen randomly, Random sampling is being used here.
5 goes into the 5 in 52,500 one time. 5-5 is 0. 5 doesn't go into 2 so put a 0. 5 goes into 25 five times. 25-25 is 0. 5 goes into 5 one time. subtract and add the zeros at end. And you get 10,500
