If you want to play conservatively, go for the lending options (these days many major exchanges do so "safely", and the reward is fixed. If you want to risk more, trade. If you want to gamble then go for the ICO.
Bounties? A tiny extra!
Basically you tell him that he can do all that if he have enough time and energy, and of course money! Trading, investing in ICO's and IEO's, gambling and lending require bankroll, more you have more easier you can make profit, cause you can try different things, with more money invested you don't need to wait x100 or much more to make some significant amount, if you have 5k for example even 10% is a lot of money, with 5 dollars you need x100 to make the same amount.
Bounties are different thing, its where you can earn some money for start. If you have good rank here on forum, or other forums, if you have many followers on social networks or blog, maybe youtube channel with many followers and you find good bounty you can earn nice money and then you can start thinking about investing that money in some service, and that can be nice passive income.