You can try your luck in gambling games but I don't think you will get that lucky and multiply that 0.005 btc of you to 0.1 btc.
I am currently looking for players to play in girlbtc. It is a block based pvp game. If you win you get your money double if not you can get back your bet as long as the other team has no bet. Maybe you can try that out. It's easier since the game only requires luck and no much effort. If you want to get an additional free 0.005 btc visit our promotion thread https://bitcointalk.org/index.php?topic=1643861.msg16759573#msg16759573