Legal hacking

I just hear of a page where you get to do some legal hacking.
You can try your skillz at this adress. First is simple. But there’s 16 levels. is absolutely the best of these… or so I think.

r2m0t. He, I’m stuck on ten. Surly the only prime between n and 2n is “3”.

I reached level 4 on the website you put up. I know I can solve it but I just cannot be bothered now.

I’m stuck at level 10 also. I don’t have the head to comprehend biographies written in German about a Russian mathematician(!)

5 < 7 < 10

7 < 11 < 14

11 < 19 < 22

I don’t know… :neutral:

I got to level 8 before I got stuck. After that I cheated :devil:

I can’t program at all and I scanned for level 1 password in the source code, so I just gave up and told myself that I was sooo not going to do this; i suck too much at it!
telnet… also not one of my skills. I have NO hacker skills…

I personally am a brute forcer - though i have dabbled in exploiting. I once did hackthissite before i believe i made level6 before i gave up.