A university event committee is forming a panel of 4 student…

A university event committee is forming a panel of 4 student speakers from a pool of 10 applicants. How many different combinations of 4 speakers can be selected if order does not matter? If the 4 selected students will speak in a specific order (introduction, keynote, response, and closing), how many different arrangements are possible? Explain the difference between the two results and why order matters in one case but not the other.