Answer
$$\frac{25}{8}\ units$$
Work Step by Step
(a) The total profit is equal to the revenue minus the cost. Thus, the total profit function is:
$$ 16x-50,000$$
(b) The break even point is where the revenue and costs are equal:
$$40x=24x+50 \\ x=\frac{25}{8}$$
Where here, the unit count is in thousands.