Hey,
I believe 50 articles can be written in about 15 days, which brings to about 3 articles a day. I have studied English for the majority of my life and have done article writing for a few companies that I worked for during my summer off.
In order for the articles to be of good quality, I think 15 days should be adequate. If you require more information about my experience in English and article writing please feel free to ask me through the emailing system of freelancer.in
I believe a 50% milestone will serve as a trust building aspect of our employer-employee relationship.
Hope to hear from you soon,
Yash Rohilla