Answer: I believe it would be 7 hours.
Step-by-step explanation: He already had $100 in his bank account so he would only need to work to pay off the remainder of the cost. So, if you do $179.99-$100 you get the remainder which is $79.99. Then you would divide $79.99 by $12.25 (his hourly pay) to find the amount of hours he would have to work. It was about 6.5 hours but you can't work for half an hour, so you would round up to 7 hours total to have enough money to pay for the TV.
I hope this helped!! Good luck :)