Probability Calculator determines the probability of an event, based on probabilities of other events. It shows the answer, and writes a report that explains how to compute the answer. Probability calculator handles problems that can be addressed utilizing three fundamental rules of probability:

1. Subtraction rule

2. Addition rule

3. Multiplication rule

### How to Use Probability Calculator

1. Determine the problem

2. Find the probability of each event

3. Type the probability in corresponding field

There is an opportunity to change the number of trials, as well as any other field in the calculator, and the other fields will automatically adjust themselves. It saves time. Probability is the measure of the likelihood of an event occurring. It is quantified as a number between 0 and 1, with 1 signifying certainty, and 0 signifying that the event cannot occur. It follows that the higher the probability of an event, the more certain it is that the event will occur. In its most general case, probability can be defined numerically as the number of desired outcomes divided by the total number of outcomes. Calculating the probability is slightly more involved when the events being dependent, and includes an understanding of conditional probability, or the probability of event A given that event B has occurred.