Which lockers are left open? (Look at details)

Question

One hundred students are assigned lockers 1 through 100. The student assigned to locker number 1 opens all 100 lockers. The student assigned to locker number 2 then closes all lockers whose numbers are multiples of 2. The student assigned to locker number 3 changes the status of all lockers who’s numbers are multiples of 3. The student assigned to locker number 4 changes the status of all the locker whose numbers are multiples of 4, and so on for all 100 lockers. Which lockers are left open?

Answer 1

Here is a detailed solution:

https://www.uccs.edu/Documents/pipes/sammi-lockprob-ans.pdf