Probability is written as a fraction.

On the top (numerator) of the fraction, we place the number of **options** we are looking for.

On the bottom (denominator) of the fraction, we place the total number of **possible combinations**.

**Example**

Look at these coloured cards.

What is the probability of selecting a yellow card at random?

**Answer**

There are 4 options that "we are looking for". This is the four yellow cards.

There are 6 "possible combinations".

The probability of choosing a yellow card is 4/6 which reduces to **2/3**.