Using the combination formula, it is found that 210 hugs occurred before the meeting.
Combination formula:
[tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by:
[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]
In this problem, there are 21 students, each hug containing 2 students, hence:
[tex]C_{21,2} = \frac{21!}{2!19!} = 210[/tex]
210 hugs occurred before the meeting.
A similar problem is given at https://brainly.com/question/24437717
