loan repayment

[esmeralda1]

A loan of 2400 can be paid with either of the 2 options below:
1. equal payments with nominal rate of interest of 7.8% convertible monthly

2. payments of 200 plus interest payments on the unpaid amount with annual effective rate of interest i

If the total payments made are equal in each of these options, find i.

The answer is 8.2%

I find the first option's monthly payment as 208.55 so the total paid amount comes to 12 times this payment which is 2502.6
But I'm confused about the second one's unpaid amount part.
How should I put it? 2502.6= (200*12) + then what?