Question 22
On June $1,$ a group of students is standing in rows, with $15$ students in each row. On June $2,$ the same group is standing with all of the students in one long row. On June $3,$ the same group is standing with just one student in each row. On June $4,$ the same group is standing with $6$ students in each row. This process continues through June $12$ with a different number of students per row each day. However, on June $13,$ they cannot find a new way of organizing the students. What is the smallest possible number of students in the group?