Introduction to probability

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Probability scales are also very useful to describe probabilities. This scale ranges from 0 to 1. 0 refers to impossibility and 1 refers to when something is certain.

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This is an example of a probability scale. As you can see on the scale, it is certain that Christmas will be on 25th December this year.

Let’s have a look at this question:

Finding probabilities

There are 6 numbers on a die. What is the probability of rolling an odd number?

Firstly, there are 3 odd numbers in total on a die: 1, 3 and 5.

This means that there are 3 possibilities. So, the probability of rolling an odd number: \frac { 3 }{ 6 } =50% chance.