another brain teaser for the math inclined

[ZeeJustin]

Hint: The problem becomes much easier if you don't leave out kid #2. I'm assuming kid #2 got lost in translation somewhere.

Answer in white: <font color="white"> Only perfect squares will be open, i.e 2, 4, 12, 16, 25, 36, 49, 64. If kid #2 was supposed to be left out, just take my answer and switch all the even doors.</font>

Reasoning: <font color="white"> Only perfect squares have an odd number of factors </font>

[lotus776]

okay, I'll try to piece it together. thank you for you help

[BigSoonerFan]

[ QUOTE ]
Hint: The problem becomes much easier if you don't leave out kid #2. I'm assuming kid #2 got lost in translation somewhere.

Answer in white: <font color="white"> Only perfect squares will be open, i.e 2, 4, 12, 16, 25, 36, 49, 64. If kid #2 was supposed to be left out, just take my answer and switch all the even doors.</font>

Reasoning: <font color="white"> Only perfect squares have an odd number of factors </font>

[/ QUOTE ]

I think you mistakenly put a couple of numbers in there and missed one!

[AleoMagus]

[ QUOTE ]
I think you mistakenly put a couple of numbers in there and missed one!

[/ QUOTE ]

Actually, just in that list, he missed two, and yeah, put a couple other extra in. Still, the answer is correct in that only perfect squares will be open.

<font color="white">1,4,9,16,25,36,49,64,81,...,961. </font>

[ZeeJustin]

[ QUOTE ]
[ QUOTE ]
Hint: The problem becomes much easier if you don't leave out kid #2. I'm assuming kid #2 got lost in translation somewhere.

Answer in white: <font color="white"> Only perfect squares will be open, i.e 2, 4, 12, 16, 25, 36, 49, 64. If kid #2 was supposed to be left out, just take my answer and switch all the even doors.</font>

Reasoning: <font color="white"> Only perfect squares have an odd number of factors </font>

[/ QUOTE ]

I think you mistakenly put a couple of numbers in there and missed one!

[/ QUOTE ]

Yeah, I'm retarded. I have absolutely no recollection of what I was thinking or how those extra numbers got in there. I guess for some reason I though 3x3 = 12. Can you prove that it doesn't?!

[lotus776]

yeah, I got it thanks

[hypermegachi]

<font class="small">Code:</font><hr /><pre> public static void main(String[] args) {
boolean[] lockers = new boolean[1000];

for (int person = 0; person &lt; 1000; ++person) {
// have each person flip every nth door
for (int i = person; i &lt; lockers.length; i += person + 1)
lockers[i] = !lockers[i]; // flip door
}

// print some lockers
for (int i = 0; i &lt; lockers.length; ++i)
System.out.print(lockers[i] + ",");
} </pre><hr />

[ QUOTE ]
true,false,false,true,false,false,false,false,true ,false,false,false,false,false,false,true,false,fa lse,false,false,false,false,false,false,true,false ,false,false,false,false,false,false,false,false,f alse,true,false,false,false,false,false,false,fals e,false,false,false,false,false,true,false,false,f alse,false,false,false,false,false,false,false,fal se,false,false,false,true,false,false,false,false, false,false,false,false,false,false,false,false,fa lse,false,false,false,true,false,false,false,false ,false,false,false,false,false,false,false,false,f alse,false,false,false,false,false,true,false,fals e,false,false,false,false,false,false,false,false, false,false,false,false,false,false,false,false,fa lse,false,true,false,false,false,false,false,false , ...

[/ QUOTE ]