Maths · Probability. The idea in plain words, the rules to remember, the mistake to avoid and a worked example, written and checked by Mega Lecture.
Probability measures how likely an event is, on a scale from 0 (impossible) to 1 (certain). It can be written as a fraction, a decimal or a percentage. When all outcomes are equally likely, the probability is the number of outcomes you want divided by the total number of outcomes.
When outcomes are not equally likely, for example with a biased spinner, we estimate the probability from an experiment. This estimate is the relative frequency. It gets closer to the true probability as the number of trials increases, so more trials give a more reliable estimate.
Outcomes that cannot happen together are mutually exclusive. If a list of such outcomes covers every possibility, their probabilities add up to 1.
Thinking a small experiment proves bias, or that a result is 'due' after a run of the other result. Each trial of a fair coin or dice is independent, and only a large number of trials gives a reliable estimate.
Answer: 60 times
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