multiple conditions in IF statement on excel

I am stuck in this part in excel.

As you see in this picture, i did a formula that says if the student pays all the balance and the remain number is 0 it will write Paid in the balance column

But if nobody registered any course and the balance also will be 0 it also shows that is paid

So i want to specify if a student registered and paid all, the balance column will write paid and if nobody registered, the balance column will be empty and if for example a student pay half of the money the remain balance will be shown in the balance column

Thank you.