Theoretical probability - GCSE Maths Definition

In GCSE Mathematics, theoretical probability refers to a probability that can be found by knowing the scenario we are dealing with.
For example, if we know we are rolling a fair, six-sided, dice, it is valid to say each outcome has an equal chance of occurring and so the theoretical probability of rolling any particular number on the dice is .

Unlike relative frequency, the dice does not have to be rolled numerous times in order for us to be able to state a probability of a particular outcome occurring. Theoretical probabilities are based on, reasonable assumptions, such as a dice or coin being fair, or that each counter in a bag is of equal size and so has an equal chance of being selected.