Which will have a higher effective interest rate:

A payday loan for [tex]$2100 due in 13 days with a fee of $[/tex]110 or a payday loan for [tex]$2100 due in 11 days with a fee of $[/tex]110?

A. A payday loan for [tex]$2100 due in 11 days with a fee of $[/tex]110, because it has the shorter period.
B. A payday loan for [tex]$2100 due in 11 days with a fee of $[/tex]110, because it has the longer period.
C. A payday loan for [tex]$2100 due in 13 days with a fee of $[/tex]110, because it has the shorter period.
D. A payday loan for [tex]$2100 due in 13 days with a fee of $[/tex]110, because it has the longer period.



Answer :

To determine which payday loan has a higher effective interest rate, we need to compare the effective annual interest rates for both loans.

First, let’s understand the concept of effective interest rate:
- The interest rate is typically calculated on an annual basis, even if the loan period is shorter than a year.
- To find the effective interest rate for a shorter period, like 11 or 13 days, we need to annualize that rate.

#### Step-by-Step Calculation:

1. Loan Parameters:
- Loan amount: [tex]$2100 - Fee: $[/tex]110

2. Loan for 13 days:
- Period: 13 days

To find the effective interest rate for this period:
- Calculate the interest for the period: [tex]\(\frac{110}{2100}\)[/tex]
- Annualize this rate to get the yearly interest rate. Since there are 365 days in a year:
[tex]\[ \text{Effective Interest Rate (13 days)} = \left(\frac{110}{2100}\right) \times \left(\frac{365}{13}\right) \times 100 \][/tex]

3. Loan for 11 days:
- Period: 11 days

Similarly, for 11 days:
- Calculate the interest for the period: [tex]\(\frac{110}{2100}\)[/tex]
- Annualize this rate to get the yearly interest rate. Again, considering 365 days in a year:
[tex]\[ \text{Effective Interest Rate (11 days)} = \left(\frac{110}{2100}\right) \times \left(\frac{365}{11}\right) \times 100 \][/tex]

After performing these steps, we find:

- For the loan due in 13 days:
[tex]\[ \text{Effective Interest Rate (13 days)} \approx 147.07\% \][/tex]

- For the loan due in 11 days:
[tex]\[ \text{Effective Interest Rate (11 days)} \approx 173.81\% \][/tex]

#### Conclusion:
- The effective interest rate for the loan due in 11 days is higher than the rate for the loan due in 13 days.

Therefore, the correct answer is:

B. A payday loan for [tex]$2100 due in 11 days with a fee of $[/tex]110, because it has the shorter period.