The probability of an event happening is, in layman's term, the odds of how likely that event can actually occur. In probability and statistics, you can determine the probability from a sample data. The sample is equal to 420 students. The number of students who wanted to take another math class is 252. Therefore, the probability of a student willing to take another math class is 252/420. Simplifying the answer, the probability is 3/5 or 60%.