This topic has been reiterated so many times, that it denotes a lack of initiative to find the information on your own. There are hundreds of topics on the matter, guides, statistics, etc. @mocacinno has spelt it out well enough on how to search around for answers.

Let me add the following: There is no way to gain merits “easily” as you put it. Most merited posts tend to put thought and effort behind, and that is down to personal capabilities and the time you are willing to invest. There are some low-ranked members that are getting a good amount of merit right from the start, and the common denominator is that they are able to communicate decently, give the brain a racket to get some ideas, and invest time into their posts. Those are the real factors that count most. People can either understand this, or remain endlessly clueless about why they get no merits.