There are 100 lockers, numbered from 1 to 100, all initially closed. A person goes by them and changes the state (if closed, opens; if opened, closes) of every other locker. This person then goes by and changes the state of every third locker, then fourth, etc. (This person always starts from the lower-numbered lockers. When doing every other locker the person first changes the state of locker 2, and when doing every third locker the person first changes the state of locker 3, etc.)
Which lockers will be closed after the person can no longer repeat this process?
Edited for clarity.