x + y = 8000,
0.03x + 0.035y = 225.
Solve this system, and you will find the amount x at 3% and the amount y at 3.5%.
Try to do it yourself.
If you still have questions, let me know.
In this case do not forget to refer to the number of this question (# 1012821) in order for I could identify it.
Good luck!