If you Really want to Earn this amount Then you have to work day and night and you need to do investment... Then you can earn this amount....
He won't need to work day and night if he has a good capital to invest for earning his desired amount, with a good capital and some understanding and knowledge anyone can get that amount from trading altcoins, people are even earning more in a month by trading altcoins with good enough capitals.
I agree many users are also recommending that kind of opportunity because we know that one of the best way to earn a lot of bitcoin in just a month. He can earn that 0.5 btc with at least 0.1 capital and i'm sure that he can reach 0.5 in less than a month if he is just smart on choosing what altcoin he gonna buy.