In probability, specific words are used to describe how likely an event is to happen. These words help explain uncertainty clearly without using numbers.

 

 

Fair

An event or situation is fair if all possible outcomes have the same chance of occurring.

 

For example, a fair coin has an equal chance of landing on each side.

 

Fairness means there is no bias towards any outcome.

 

 

An Even Chance

An even chance means that an event is just as likely to happen as not to happen.

 

This occurs when:
• there are two equally likely outcomes
• the event happens half of the time

 

An even chance lies halfway between impossible and certain.

 

 

Certain

An event is certain if it will definitely happen.

 

There is no uncertainty about the outcome.

 

A certain event happens every time the experiment is carried out.

 

 

Impossible

An event is impossible if it cannot happen.

 

There are no outcomes that make the event occur.

 

An impossible event will never happen, no matter how many times the experiment is repeated.

 

 

Likely

An event is likely if it has a high chance of happening, but it is not guaranteed.

 

A likely event happens more often than it does not.

 

However, there is still some uncertainty, so it may not occur every time.

 

 

Unlikely

An event is unlikely if it has a low chance of happening, but it is still possible.

 

An unlikely event happens occasionally, but not very often.

 

Unlikely does not mean impossible.

 

 

Comparing the Terms

From least likely to most likely, the terms can be ordered as:

Impossible
Unlikely
Even chance
Likely
Certain

 

Each term describes a different level of likelihood.

 

 

Key Points to Remember

Fair means all outcomes are equally likely.
An even chance means an event is as likely to happen as not.
Certain events will definitely happen.
Impossible events cannot happen.
Likely events have a high chance of occurring.
Unlikely events have a low chance but are still possible.

 

Using these terms correctly helps describe probability situations clearly and avoids confusion when discussing chance, uncertainty and risk.