Is it possible to have a good rank in google Only with the help of article marketing? If yes then how many articles i should submit everyday.
Article submissions is one of the lowest tier methods for increasing your search results position. You want all the unique content for your website, if this content is of high quality and useful to visitors you'll find your backlinks will come naturally from related websites.
Yes, it is possible to achieve a good ranking based on article marketing alone. (at least for non-competitive terms). It's not adviceable though, since you can get a lot stronger link profile by using more than one method. It's not possible to give you an answer to your second question, since the competition depends on the targeted keyword. For "blue hats to wear in the summer", an article or two would probably be enough, while for "cheap loans", you would probably need a billion squillion articles.
yes, article marketing can help, but with any type of thing (such as investing, etc) diversification is the key. Use article marketing, but don't just use ONLY article marketing.