GFY: Math Challenge
 

Well my girlfriend works in an actuarial department (basically math geeks) and they have from time to time. So here was a math problem that was forwarded to the office group. See if you can get it.




There is a number (n) that is composed of 3 digits such that when squared, it's result has only even numbers. When (n+500) is squared, it has a result that is comprised of only even numbers.

What is n?

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4

69

unless you worded it wrong... or i read it wrong... there seems to be a lot of possible answers.

yah I think its worded wrong also,

all 3 digit numbers that are even, would be even when squared,

so thats like half the numbers from 100 to 998

and adding 500 to them still means they are even, no matter what the number, so its square would also be even,

???

He didn't say the number was merely even, it is comprised of all even digits.

SpaceAce

I know this much.....

Its a prime number :thumbsup

Regards,

Lee

your right, not is a even number, is comprised only of even numbers

ok

you are all impicbles, the answer is 112.5

that still leaves a lot of possibilities..

I didn't say (n) was even. I said (n)^2 has all even digits and (n+500)^2 has all even digits.

on that note...
what the fuck is an impicble?

462

Did i win?

168 times 168 is 28224 and 668 times 668 is 446224

n = 168

what do I win?

I know. I was trying to point that out to everyone who thought the resulting number had to be merely even. I wasn't talking about n, I was talking about it's square.

SpaceAce

Mind explaining how you got to that figure?

ONE MEEEELION DOLLARS!

Good job.

Beat me to by about 5 secs......:(

the power of PHP =)

http://www.wantsmut.com/square.php

:1orglaugh :1orglaugh

I wrote a PERL program to figure it out for me. My g/f used Excel. Here is my code:

<pre>

for($n=100;$n<999;++$n) {
print "$n \n";
if(allEven($n) && allEven($n+500)){
print "\n\nI GOT IT! THE # is -> $n\n\n";
exit(1);
}
}

sub allEven{
$num1 = shift;
$num = "" . $num1**2;
$retVal = 1;
for($i=0; $i<length($num);++$i){
# print " TRYING $num length = " . length($num);
$k = substr($num,$i,1);
if($k%2 hahahaha 0){
$retVal &= 1;
}
else{
$retVal = 0;
}
}

return $retVal;

}

</pre>

nice job!!!

Son of a bitch.... i just got here... and just figured it out on excel

168 is correct

give us more of these :thumbsup

4

Yeah. I was agreeing with you.. I was just re-stating your quote and trying to further explain what the question was.

that was an ugly bump :(