The outcomes of an experiment are equally likely to occur
when the probability of each outcome is equal. In other words,
when the chances of two things happening are the same, they
are said to be equally likely.
For example, when an unbiased coin is tossed it is as likely
to land heads up as tails up, while an ordinary dice has an
equal chance of landing with any one of 1, 2, 3, 4, 5, or
6 on top..