There's Too Many Numbers To List Out!

Number Theory Level 1

$\begin{aligned} && 3,6,9,12,15,\ldots \\ &&5,10,15,20,25, \ldots \\ &&7,14,21,28,35,\ldots \end{aligned}$

The above shows 3 distinct arithmetic progressions. What is the smallest number that appears in all 3 rows?