# What is a prime number between 10 and 20?

May 22, 2016

The numbers $11$, $13$, $17$ and $19$ are all prime numbers between $10$ and $20$.

#### Explanation:

A prime number is a number that is only divisible by itself and $1$.

To say that a number is even is to say that it is divisible by $2$. As a result, the only even prime number is $2$ itself.

So the only possibilities to consider are the odd numbers between $10$ and $20$, namely:

$11$, $13$, $15$, $17$, $19$

Of these, all are prime except $15$:

$15$ is divisible by $15$, $5$, $3$ and $1$, so is not a prime number.