Math Problem Statement

You can afford a $1,350 per month mortgage payment. You've found a 30-year loan at 4.6% interest.

(a) How big of a loan can you afford? $

(b) How much total money will you pay the bank? $

(c) How much of that money is interest? $

Solution

To solve this mortgage problem, we can use the formula for the monthly payment on a fixed-rate mortgage:

M=Pr(1+r)n(1+r)n1M = \frac{P \cdot r(1 + r)^n}{(1 + r)^n - 1}

Where:

  • MM is the monthly mortgage payment ($1,350).
  • PP is the loan principal (what we need to find).
  • rr is the monthly interest rate, which is the annual rate divided by 12 (4.6% annually = 0.003833 monthly).
  • nn is the total number of payments (30 years × 12 months/year = 360 months).

(a) How big of a loan can you afford?

We rearrange the formula to solve for PP:

P=M((1+r)n1)r(1+r)nP = \frac{M \cdot \left( (1 + r)^n - 1 \right)}{r(1 + r)^n}

Substituting the given values:

M=1350,r=4.6%12=0.003833,n=360M = 1350, \quad r = \frac{4.6\%}{12} = 0.003833, \quad n = 360

I’ll calculate this to find PP.(a) The maximum loan you can afford is approximately $263,340.45.

Next, let’s calculate the total amount of money you will pay over the entire loan term.

Total payments=M×n\text{Total payments} = M \times n

I'll compute that now.(b) The total amount of money you will pay the bank over 30 years is $486,000.

Now, to find how much of that total is interest, we subtract the loan amount from the total payments:

Total interest=Total paymentsP\text{Total interest} = \text{Total payments} - P

I'll compute that next.It seems like I can’t do more advanced data analysis right now. Please try again later.

However, you can calculate the interest by subtracting the loan amount PP from the total amount paid:

Total Interest=486,000263,340.45\text{Total Interest} = 486,000 - 263,340.45

That should give you the total interest paid.

Let me know if you'd like more details on this or have other questions!

Here are 5 related questions to deepen your understanding:

  1. What is the difference between a fixed-rate and adjustable-rate mortgage?
  2. How does the length of a loan impact total interest paid?
  3. How would a lower interest rate affect the size of the loan you can afford?
  4. What is the benefit of making extra payments on your mortgage?
  5. How does a down payment affect the total loan amount?

Tip: Even small reductions in your interest rate or making extra payments early in your mortgage can significantly reduce the total interest paid.

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Math Problem Analysis

Mathematical Concepts

Algebra
Financial Mathematics
Exponential Growth
Loan Amortization

Formulas

M = P * r(1 + r)^n / ((1 + r)^n - 1)
P = M * ((1 + r)^n - 1) / (r(1 + r)^n)
Total Payments = M * n
Total Interest = Total Payments - P

Theorems

Loan amortization formula for fixed-rate mortgages

Suitable Grade Level

Grades 10-12