A worker gets $9/hr for a regular work day and $13.50/hr for additional hours. If he was paid $114.75 for an 11hr work day, how long is a regular work day?

1. I did 9x8 since you usually work 8 hours a day but did not give answer, so I add or subtracted 0.5 to 8.

2. i did 9*7.5=67.5, keep in mind that he worked for 11 hrs that day so 11-7.5=3.5 hours left

3. then I subtracted 67.5 from 114.75 and got 47.25

4. I divided 3.5 by 47.25 and got 13.5