To find out how many students are not using any of the three methods, we need to subtract the number of students who used at least one method from the total number of students.
First, let's determine the number of students who used at least one method:
35 drove alone.
35 rode in a carpool.
30 rode public transportation.
3 used both carpools and public transportation.
6 used both a carpool and sometimes their own cars.
6 used buses as well as their own cars.
1 used all three methods.
To calculate the total number of students who used at least one method, we add up these numbers:
35 + 35 + 30 + 3 + 6 + 6 + 1 = 116
Now, we subtract the total number of students who used at least one method from the total number of students in the poll:
100 - 116 = -16
Since we can't have negative students, it seems there was an error in the data. The total number of students who did not use any of the three methods cannot be determined with the provided information.