Hi I will invest to any idea about earn bitcoin. I would start from 0.1 BTC. If everything will be ok I pay more more money

I wait for PW

You could try investing in p2p bitcoin lending platforms. Bitbond for example has ~20% interest loans.
It has lot of risk to do this , even you lend in those reputable sites and at least have a chance for scamming your money.
"No Collateral , No Loan" you must take this motto whatever situation about borrower you must asking about collateral.
But , you can lend your money here in bitcointalk.org , then you can asked them for collateral .
Most of these bitcoin lending sites now have a comprehensive sign up process for borrowers. Proof of income, proof of residence, passport copy, live video session... so I think it's not quite as risky as youre making it out to be.
Definitely invest with caution though, and preferably in borrowers with good ratings.