At a school there are 800 students and 800 lockers, numbered 1 through 800. Suppose the first student opens each locker. The second student then closes every second locker. The third student then comes along and decides to change the state of every third locker(that is, closes the ones that are open and opens the one that are closed). The fourth student then changes the state of every forth locker. This process continues until the 800th student changes the state of the 800th locker. Which lockers are open????
Pre_Calculus Word Problem (opening, closing lockers)
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pka
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Take a look at this web page:
http://mathforum.org/library/drmath/view/55812.html
http://mathforum.org/library/drmath/view/55812.html
arthur ohlsten
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every number has an even number of factors, except perfect squares. example
factors of 12 1,12 2,6 3,4 even
factors of 16 1,16 2,8 4 odd
Every locker door has its state changed an even number of times EXCEPT lockers number 1,4,9,16,25, 36... 784
Arthur
factors of 12 1,12 2,6 3,4 even
factors of 16 1,16 2,8 4 odd
Every locker door has its state changed an even number of times EXCEPT lockers number 1,4,9,16,25, 36... 784
Arthur