Its not very easy...but yes if you plan well you can achieve far more than this. First have lots of patience, chose the right topic (it is not only about the volume of visitors but about relevant visitors), your website should be easy to navigate, it should have good number of advertisers (like travel, jobs, health or business domain), get quality content and right meta tags, good ad placements...and then you can do other seo activities like article writing, press release and link building. Hard work pays...and if it is Adsense it pays very well
Yes, that would achievable if you have sites with lots of traffic. @jhonhijet Nice income. Could you share to us at least one of your blog?