Probability Mind Map

Probability of an event is a number that shows how likely that event is to happen.

First write the sample space or total number of outcomes, then count only the favourable ones.

Equally likely outcomes are outcomes that have the same chance of happening in an experiment.

Always ask first: is the coin, die, or spinner fair before applying the counting formula?

The sample space for a coin toss is the set of all possible outcomes of that toss.

When more than one coin is tossed, write outcomes in order so you do not miss any case.

The sample space for throwing a die once is the set of all possible faces that can appear.

For a single die, always write all six faces before starting any probability calculation.

For equally likely outcomes, probability of an event equals favourable outcomes divided by total outcomes.

Write the event first, then count only matching outcomes before dividing by the total.

An impossible event is an event that cannot happen in a given experiment.

If the event has no favourable outcomes, stop and write probability 0.

A certain event is an event that must happen in a given experiment.

If every outcome in the sample space supports the event, the probability is 1.

The complement of an event is the event that the original event does not happen.

Use complement when the opposite event is easier to count than the original event.

This is the use of probability when one or more cards are chosen from a deck or a card set.

For card problems, first decide whether the question asks about suit, colour, rank, or face card.

This is probability applied to a spinner or a bag where each sector or item may represent an outcome.

For spinners, check equal parts. For bags, count the exact number of items of each type.

Comparing likelihood means deciding which event is more likely by comparing their probabilities.

Convert probabilities to the same form before deciding which event is more likely.

A probability value is valid only if it lies between 0 and 1, including both ends.

After solving, quickly test your answer: is it between 0 and 1? If not, recheck the counting.