We can solve this problem by first calculating for the total cost and the total revenue. Then the difference of the total revenue and total cost would be the profit or return on investment.
Profit = Total revenue – Total cost ---> 1
First, calculating for the total revenue:
Total revenue = $86 * 120,000
Total revenue = $10,320,000
Second, calculating for the total cost:
Total cost = X * 120,000
where X is the target cost for one littlelaser
It was stated that the company wants a return of investment of 18%, therefore the profit must be:
Profit = 0.18 * $12,000,000
Profit = $2,160,000
Substituting to equation 1:
$2,160,000 = $10,320,000 - X * 120,000
X = $68
Therefore the target cost is $68