Hi, I've got another question for you math smarties out there! But this time, I think I know the answer and would like you to help me check if it is right. This is the question.

Karla borrows some money from Ginny at 6.9%/a compounded monthly. 2 years ago Karla paid Ginny $5700 towards the principal and the interest. After another 2 years, she paid Ginny another $5700. And after 8 years, Karla finally paid off all her debt to Ginny with $28 500. How much interest did Ginny receive from Karla?

So I solved for the 'Present' value and then I took the amount of money Karla paid Ginny and subtracted the present value from it to find this number: $18122.27 as my answer. Can you check this please?

Do NOT write down the steps please. Just tell me if it is right or not, thank you! :D