Question

Your parents are purchasing a mobile home for $89,000. The sales tax is 4.2%, they make a $3,000 down payment, and they have an excellent credit score. How much is the interest at the end of the second month if their first month’s payment is $925.67?

Answer 1

i assumed the length of the loan was 10 years because that yielded a realistic interest rate of 4.399% using a finance calculator
The balance to be paid off is 89,000 plus sales tax minus 3000 down payment
--> 89,000*1.042 - 3000 = 89,738
Interest at end of first month is 89,738*(i/12) where i is int rate of 4.399%
= 89738*(.04399/12) = 328.96
Subtract this from 1st payment to get amount of principle paid
-->925.67 - 328.96 = 596.705
Subtract from Balance to get new balance
-->89,738 - 596.705 = 89,141.29
interest at end of 2nd month is new balance*(i/12)
--> 89,141.29*(.04399/12) = 326.78

**Note if loan is not for 10 years then this answer is wrong but you didn't provide that info**