From the statement of the problem, we know the following data of the mortgage:
• t = time = 30 years,
,
• P = principal = $100,000,
,
• r = interest rate in decimal = 7/100 = 0.07.
The monthly payments are given by the following formula:

Replacing the data of the problem, we find that the monthly payments will be:

dollars.
The money that Aaron will pay in a year is 12 times the value of the monthly payment:
total of a year = 12 * $665.302 ≅ $7983.63.
Answer
Aaron will pay $7983.63 in a year.