Students are lined up in the playground for a drill and only know that the number of people is between 90-110. If they are lined up in 3 rows they are no more or less: if they are lined up in 5 rows they are 2 less, and if they are lined up in 7 rows they are 4 less.
. No more or less if in rows of 3: 2 less if in rows of 5 and 4 less if in rows of 7.
All can be interpreted as 3 more than a multiple of 3, 5, or 7
The least common multiple of 3, 5, and 7 is 105
Then the number of students is: 105+3=108