[IndianAstronaut]

In addition to what others are saying I can't stress enough how important combinatorics are as well. Definitely spend some time trying to understand this area. From there move on to stochastic processes.

[carlsednaoui]

Thanks for the note! This looks like a good place to start: https://www.khanacademy.org/math/probability/probability-and...

Would you agree?

[IndianAstronaut]

Looks good. I used "Fundamentals of Probability with Stochastic Processes" by Ghahramani. Very good book.