#### Explanation:

From the ratio, the fraction of labor cost is $= \frac{3}{2 + 3 + 1} = \frac{3}{6} = \frac{1}{2}$.

So, let the total cost of the tablet is $$x$. So, labor cost $= \frac{1}{2} \times x = \frac{x}{2}$. $\therefore \frac{x}{2} = 300$$\therefore x = 600$. So, the total cost of the tablet is$$600$. (Answer).