How Much Math Does an IT Engineer Need to Learn for Data Science

This was from a self study IT engineer but read the comments in this article

https://www.kdnuggets.com/2017/12/mathematics-needed-learn-data-science-machine-learning.html

http://quantlabs.net/blog/2017/12/how-much-math-does-an-it-engineer-need-to-learn-for-data-science/