Home Loan Payments
1. **Stating the problem:** You want to buy a $218,000 home, pay 10% down, and take out a 30-year loan for the rest. We are asked to find:
a) The loan amount.
b) Monthly payments at 6% interest.
c) Monthly payments at 7% interest.
2. **Calculate the loan amount:**
Down payment = 10% of $218,000 = $$218000 \times 0.10 = 21800$$
Loan amount = Purchase price - Down payment
$$218000 - 21800 = 196200$$
3. **Monthly payment formula:** The monthly payment for a loan is calculated by:
$$M = P \frac{r(1+r)^n}{(1+r)^n - 1}$$
where
$P$ = loan amount,
$r$ = monthly interest rate = annual rate / 12,
$n$ = total number of payments = years \times 12.
4. **Calculate monthly payment at 6% interest:**
Annual interest rate = 6% = 0.06
Monthly interest rate: $$r = \frac{0.06}{12} = 0.005$$
Number of payments: $$n = 30 \times 12 = 360$$
Plug values into formula:
$$M = 196200 \times \frac{0.005(1+0.005)^{360}}{(1+0.005)^{360} - 1}$$
Calculate $(1+0.005)^{360}$:
$$ (1.005)^{360} \approx 6.022575$$
Now,
$$M = 196200 \times \frac{0.005 \times 6.022575}{6.022575 - 1} = 196200 \times \frac{0.0301129}{5.022575} = 196200 \times 0.0059961 \approx 1175.25$$
5. **Calculate monthly payment at 7% interest:**
Annual interest rate = 7% = 0.07
Monthly interest rate: $$r = \frac{0.07}{12} \approx 0.0058333$$
Number of payments:
$$n = 360$$
Calculate $(1+0.0058333)^{360}$:
$$ (1.0058333)^{360} \approx 10.6771$$
Now,
$$M = 196200 \times \frac{0.0058333 \times 10.6771}{10.6771 - 1} = 196200 \times \frac{0.062284}{9.6771} = 196200 \times 0.006436 \approx 1262.83$$
**Final answers:**
a) Loan amount = $196,200
b) Monthly payment at 6% = $1175.25
c) Monthly payment at 7% = $1262.83