Shaniqua brings home $250 per week working 25 hours. She is able to save $30 of her earnings each week. Shaniqua wants to have $750 saved at the end of 15 weeks. She is allowed to work up to 30 hours per week if she wants. She can save all the money earned working extra hours. How many hours (as a whole number) each week must Shaniqua work to save $750 at the end of 15 weeks? Show your work