Question

how much money will be spent in interest alone over the course of the 5% 30-year mortgage described in the table?
mortgage payments
principal: $120,000.00
interest rate | monthly payment
3% | $506
4% | $573
5% | $644
$?

Explanation:

Step1: Calculate total payments over 30 years

There are 30 years, and each year has 12 months, so total months = 30 12 = 360. The monthly payment for 5% interest is $644. So total payments = 644 360.
$$644\times360 = 231840$$

Step2: Subtract principal to find interest

The principal is $120,000. So interest = total payments - principal = 231840 - 120000.
$$231840 - 120000 = 111840$$

Answer:

111840