Giuga Number/Examples/30

Example of Giuga Number
$30$ is a Giuga number (the smallest):
 * $\dfrac 1 2 + \dfrac 1 3 + \dfrac 1 5 - \dfrac 1 {30} = 1$

Proof
We have that:
 * $30 = 2 \times 3 \times 5$

Then:

Hence the result by definition of Giuga number.