A mother earned ​$7500.00 from royalties on her cookbook. She set aside​ 20% of this for a down payment on a new home. The balance will be used for her​ son's future education. She invests a portion of the money in a bank certificate of deposit​ (CD account) that earns​ 4% and the remainder in a savings bond that earns​ 7%. If the total interest earned after one year is ​$360.00​, how much money was invested at each​ rate?