# Thread: How many open Lockers

1. ## How many open Lockers

There are 100 students all in a line. There are also 100 lockers - all in a line and all shut. The first student walks down the line of lockers opening the lockers. The second student goes down the line of lockers closing every second locker. The third student goes down the line of lockers changing the status of every third locker (closing it if it is open, opening it if it is shut). The fourth student goes down the line of lockers changing the status of every fourth locker. etc etc etc until the 100th student goes down the line of lockers and changes the status of the 100th locker.

At the end of all this - how many lockers are open?

2. ## Re: How many open Lockers

I get <span style="background-color: #FFFF00; color: #000000; font-weight: bold"><font color=yellow>10, the squares of the first 10 numbers:
1,4,9,16,25,36,49,64,81,100</font color=yellow></span hi>

Steve

3. ## Re: How many open Lockers

Yup

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