Answer
$15,504$ different groups.
Work Step by Step
The order in which the students are selected is not important. It is a combination of five students from a group of 20 students.
$_{20}C_5=\frac{20!}{(20-5)!~5!}=\frac{20\times19\times18\times17\times16\times15!}{15!~5!}=\frac{1,860,480}{120}=15,504$
