You might give your answers in exact, product, or factorial (if applicable) form, but if the former, please describe how they would first be set up in product or factorial form.
A college pep band is made up of the 20 members.
a. If the band director chooses 5 performers to march in the front row, how many ways can he select 5 members out of the 20 available members?
b. If the band director calls for 5 performers to march in front row, then specifies how they will be arranged from left to right, how many ways can he do this from the 20 available members?