Hi alltimeacheiver!

The question asks for the number of boxes the manufacturer needs to sell in order to make a profit of 110,000. Since we do not know the number of boxes, let's define that as our variable:

N = number of boxes sold

We also need to think about the equation for Profit:

Profit(from N boxes) = Revenue(from N boxes) - Cost(of N boxes)

Now we can catalog what we know and solve for what we do not!

Profit: this is given as $110,000

Revenue: if the selling price of each box is $560 and we sell N boxes, the total revenue would be $560*N.

Cost: a bit trickier because cost is given by the unit. We are told that there are 50 units in each box, and that each unit costs $9. So, the cost per box would be 50*$9 = $450. So, using the same logic as we did for revenue, if the cost per box is $450 and we sell N boxes, the total cost is $450*N.

Putting it all together:

Profit(from N boxes) = Revenue(from N boxes) - Cost(of N boxes)
$110,000 = $560*N - $450*N
$110,000 = $110N
N = 1000

The correct answer is [spoiler]D[/spoiler].

I hope this helps!

Whit