Probability, a high-school math staple, often gathers rust in our memories. In this blog, we refresh its concepts through a machine learning lens, delving into Probability Mass Function (PMF). By the blog’s end, readers gain insights into probability, distribution, PMF’s expectations, and variance—crucial aspects in machine learning. The code snippet illustrates PMF for a biased coin toss, emphasizing its role in predicting outcomes. Bridging probability theory and machine learning, the blog fosters a deeper understanding of these essential concepts.