Sam needs to take out a personal loan for \$8,900 to pay for a trip to Europe with his classmates. His bank has offered him the four loans listed in the chart below. If all of the loans are compounded monthly, which of the four loans will give Sam the lowest monthly payment?

\begin{tabular}{|c|c|c|}
\hline
Loan & Term (months) & Interest Rate \\
\hline
A & 12 & 9.50\% \\
\hline
B & 24 & 8.75\% \\
\hline
C & 36 & 7.75\% \\
\hline
D & 48 & 6.60\% \\
\hline
\end{tabular}

a. Loan A
b. Loan B
c. Loan C
d. Loan D



Answer :

To determine which loan offers Sam the lowest monthly payment, we need to calculate the monthly payment for each loan option. The formula for the monthly payment on a loan (with monthly compounding interest) is:
[tex]\[ M = P \frac{r(1+r)^n}{(1+r)^n - 1} \][/tex]
where:
- [tex]\( M \)[/tex] is the monthly payment,
- [tex]\( P \)[/tex] is the loan amount,
- [tex]\( r \)[/tex] is the monthly interest rate,
- [tex]\( n \)[/tex] is the number of monthly payments (loan term in months).

Given the loan amount [tex]\( P = \$8,900 \)[/tex], let's calculate the monthly payments for each loan option one by one.

### Loan A:
- Annual interest rate: [tex]\( 9.5\% \)[/tex]
- Monthly interest rate: [tex]\(\frac{9.5}{100 \times 12} = 0.00791667 \)[/tex]
- Loan term: [tex]\( 12 \)[/tex] months

Using the formula:
[tex]\[ M_A = 8900 \times \frac{0.00791667 \times (1 + 0.00791667)^{12}}{((1 + 0.00791667)^{12} - 1)} \][/tex]

This results in:
[tex]\[ M_A = 780.38 \][/tex]

### Loan B:
- Annual interest rate: [tex]\( 8.75\% \)[/tex]
- Monthly interest rate: [tex]\(\frac{8.75}{100 \times 12} = 0.00729167 \)[/tex]
- Loan term: [tex]\( 24 \)[/tex] months

Using the formula:
[tex]\[ M_B = 8900 \times \frac{0.00729167 \times (1 + 0.00729167)^{24}}{((1 + 0.00729167)^{24} - 1)} \][/tex]

This results in:
[tex]\[ M_B = 405.57 \][/tex]

### Loan C:
- Annual interest rate: [tex]\( 7.75\% \)[/tex]
- Monthly interest rate: [tex]\(\frac{7.75}{100 \times 12} = 0.00645833 \)[/tex]
- Loan term: [tex]\( 36 \)[/tex] months

Using the formula:
[tex]\[ M_C = 8900 \times \frac{0.00645833 \times (1 + 0.00645833)^{36}}{((1 + 0.00645833)^{36} - 1)} \][/tex]

This results in:
[tex]\[ M_C = 277.87 \][/tex]

### Loan D:
- Annual interest rate: [tex]\( 6.60\% \)[/tex]
- Monthly interest rate: [tex]\(\frac{6.60}{100 \times 12} = 0.0055 \)[/tex]
- Loan term: [tex]\( 48 \)[/tex] months

Using the formula:
[tex]\[ M_D = 8900 \times \frac{0.0055 \times (1 + 0.0055)^{48}}{((1 + 0.0055)^{48} - 1)} \][/tex]

This results in:
[tex]\[ M_D = 211.47 \][/tex]

### Comparison of monthly payments:
- Loan A: [tex]\( 780.38 \)[/tex]
- Loan B: [tex]\( 405.57 \)[/tex]
- Loan C: [tex]\( 277.87 \)[/tex]
- Loan D: [tex]\( 211.47 \)[/tex]

The lowest monthly payment is given by Loan D ([tex]\( 211.47 \)[/tex]).

Therefore, Sam should choose Loan D for the lowest monthly payment.

_Answer: d. Loan D_