I am in need of at least a 15 bitcoin loan because I have lost more than I can afford in the recent crash. I will repay my loan within 20 days and repay with 18 bitcoin. I can send any proof you need of myself before you trust me with your money. Thank you.
3 bitcoins interest in 20 days?

Feels pretty scammy to me. You'll have to provide something that can be easily sold for $11,000 should you not be able to pay back the coins.
Don't have something worth $11,000? You won't get this "loan".