To determine which investment produces a $5 hourly profit for a candy shop, earning $1 profit per pound of candy, we have to analize each option.
1- Worker at $10 per hour, producing eight pounds of candy per hour. This option results in a $2 loss per hour, since the earnings are lower than the costs (8-10= -2).
2- Worker at $12 per hour, producing 16 pounds of candy per hour. This one results in a $4 profit, as the cost is lower than the earnings (16-12= 4).
3- Machine with $5 per hour operating cost, producing 10 pounds of candy per hour. Here we have a $5 profit, as the cost is of $5 and the earnings are of $10 (10-5= 5).
4- Machine with $8 per hour operating cost, producing 14 pounds of candy per hour
. In this option, we have a $6 profit (14-8= 6).
So, the investment that produces a $5 hourly profit for a candy shop earning $1 profit per pound of candy is the third option, that is, a machine with $5 per hour operating cost, producing 10 pounds of candy per hour.