What is Probability?
Probability is measuring how likely an event will occur [1]. It can be shown as fractions, decimals, or percentages. The probability will range from 0 to 1 when working with fractions or decimals, while it ranges from 0 to 100% when working with percentages. The probability of a certain event “A” is denoted as P(A).
In the following lessons, you will be learning more about the basic probability laws [2].
You will first learn the addition rule, which is used to calculate the probability that one or both events occur.
Then, you will learn about the multiplication rule, useful for calculating the probability that both events will occur together.
Finally, you will be introduced to the complement rule, which tells you that the sum of all the probabilities for all possible outcomes is equal to 1.
Before using these probability laws, it would be useful to make yourself familiar with the types of events that can occur in probability.
These are events that cannot occur at the same time.
E.g. When you roll a six-sided die once, you cannot roll a 2 and an odd number at the same time. These events are mutually exclusive.
Mutually Exclusive Events
These are events whose probability does not change based on the outcome of another event.
E.g. When rolling two dice, rolling a 2 (or any other number) on the first roll doesn’t affect whether you will roll an odd number on the second roll. These events are independent.
Independent Events
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