probability

This is the term used when discussing how likely it is that something will happen.

Probability is usually expressed as a fraction between 0 (something that’s totally impossible) and 1 (something that’s certain of happening).

For example, there are six possible results when a dice is thrown:

    1, 2, 3, 4, 5, 6.

The probability of the dice landing on any one of these numbers is \dfrac{1}{6}.

The fraction’s denominator shows the number of possible events, and the numerator shows the number of results which represent the ‘successful’ event.

When events are independent, the total of their probability is 1.

For example, when a dice is thrown:

    P (six) + P (not six) = 1