Impossible : An event is impossible if it has a probability of 0.

Outcome : A result of a random experiment.

Probability : A probability is a number between 0 and 1 that describes how likely an outcome is. For discrete events that are equally likely the probability can be calculated by dividing the number of favorable outcomes by the number of possible outcomes.

Unlikely : An event in a probability experiment in unlikely if the probability of it happening is low.

Median : The median of n numbers is defined as the $\frac{n}{2}$-th biggest number in case of even $n$ and as the average of the $\frac{n-1}{2}$-th biggest number and the $\frac{n+1}{2}$-th biggest number in case of odd $n.$ The median of numbers is a statistic that can be representative of a typical element of a collection of numbers. It is an alternative to the average of numbers.

Number : A number $x$ is a mathematical symbol representing a quantity.

Third : A third either refers to the third object in an ordering or to the number $\frac{1}{3}=0.\overline{3}.$

Division : Division is the mathematical operation that divides objects equally into groups. More generally $x\div y$ is defined as the number that if multiplied by $y$ equals $x.$

Favorable outcome : In a random experiment the favorable outcomes are the outcomes of the event of which we want to calculate the probability. For example if we want to calculate the probability of throwing an even number with a dice the favorable outcomes are 2, 4 and 6.

Number : A number $x$ is a mathematical symbol representing a quantity.

Outcome : A result of a random experiment.

Possible outcome : Any outcome of a random experiment.

Probability : A probability is a number between 0 and 1 that describes how likely an outcome is. For discrete events that are equally likely the probability can be calculated by dividing the number of favorable outcomes by the number of possible outcomes.