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Download now on Google Play**Basic terms on probability:**

Now we learn about some basic terms on probability. That is,

- Random experiment or trial.
- Outcome.
- Sample point.
- Sample space.
- Event.

1. Random experiment or trial:

A trial is an action which results in one or several outcomes.

Example:

Rolling dice and tossing a coin are trials.

2. Outcome:

The results obtained after the performance of the trial or experiment or operation is called an outcome.

Example:

**1)**While flipping a coin, we get head or tail. Head and tail are called outcomes.

**2)**When we are rolling a die, there are \(6\) certain probability results in \(1\), \(2\), \(3\), \(4\), \(5\), \(6\) which are called outcomes.

3. Sample point:

Each outcome of a random experiment is called a sample point.

While flipping a coin, each outcome \(H\) or \(T\) is the sample points.

4. Sample space:

The set of all possible outcomes (or sample points) of a random experiment is called the sample space.

In a single flip of a coin, the collection of sample points is given by \(S =\) \({H, T}\).

If two coins are tossed the collection of sample points \(S = {(HH),(HT),(TH),(TT)}\).

It is denoted by \(S\). The number of elements in it is denoted by \(n(S)\).

5. Event:

Any subset of a sample space is called an event.

If a dice is rolled, it shows \(4\), which is called an outcome (since it is a result of a single trial).

**Even denoted as**\(E\)

**and the number of events is denoted as**\(n(E)\)

**which is nothing but the total number of events.**

In the same experiment, the event of getting an even number is \({2,4,6}\).

Therefore here the total number of events \(n(E) = 3\).

Hence an event can be one or more than one outcome.