What can fit in to 100 and 39 evenly

For a study comparing leisure activities of physical education students with those of other students, a researcher has randomly selected a ten percent sample of physical education students and one percent sample of non-physical education students for a list of students. what kind of sampling technique is this?

Which of the following refers to treating all patients or first aid victims as a potential source of bloodborne pathogens by taking all precautions to prevent contamination?

Pleas give me brief explanation about deterministic model in advanced hydrology