Question

if a group of students are facing each other in a circle and student 2 is facing student 9 how do i find out how many students are in the circle

Answer 1

Then student 1 must be facing student8. Pretend it is a clock.

at 12, student1
at six, student 8
at 3 student 4
at 9 student 12
if you could, at 12 put student 16, but the clock is full. 15 students?