There are 1,000 lockers in the long hall of Westfalls
High. In preparation for the beginning of school, the janitor cleans the
lockers and paints fresh numbers on the locker doors. The lockers
are numbered from 1 to 1,000. When the 1,000 Westfalls High students return
from summer vacation, they decide to celebrate the beginning of the school
year by working off some energy.
- Student 1 opens every locker.
- Student 2 either opens or closes every
- Student 3 opens or closes every third
locker. And so on, ...
locker doors are open when every student finishes?