This article aims at providing some intuition for what random variables are and why random variables are useful and needed in probability theory.

## Intuition for random variables

Informally speaking, ** random variables encode questions about the world in a numerical way**.

How many heads can I get if I flip a coin 3 times?

How many people will vote the Democrats at the US presidential elections?

I want to make pizza. What is the possible overall cost of the ingredients, considering all combinations of different brands of them?

These are all examples of random variables. **What a random variable does**, in plain words,** is to take a set of possible world configurations and group them to a number. **What I mean when I say *world configurations *will be clearer soon, when talking about the *sample space * (which, appropriately, is also called *universe*).

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