The answer depends on so many factor and most important of them all is the quality of the article.
I can write a unique, 500 words articles in about 3 minutes by just smashing my fingers across my keyboard writing whatever comes into my mind. While that article will still be on topic, it won't have any real value for the readers.
On the other hand, if I'm writing content for my personal blog where I post SEO case studies and results of my experiment, it would take a lot more than just a few minutes to put together a well researched article... some that will make my readers WANT to signup subscribe to my blog.