Answer: 55hours
Step-by-step explanation: divide $320 by 40 to figure out how much money you earn an hour, in this case you earn $8 every hour. To do things easier and faster, since you now know how much money you earn an hour you can divide $440 (the money you want) by $8 (the amount you earn) to figure out how much hours it would take, to which it would take 55 hours to make $440.