You owe $976.34 on a credit card that has an interest rate of 10.75%

APR. You pay $100.00 at the end of each month. Calculate the
difference between the interest accrued by a $976.34 balance on
the credit card and what $100.00 would earn in a savings account
that has an interest rate of 2.75% APR over the span of one month.

1 answer

To calculate the interest accrued on the credit card balance and the interest earned in a savings account, we can follow these steps:

Step 1: Calculate the interest accrued on the credit card

The formula to calculate the interest accrued for one month for a credit card is:

\[ \text{Interest} = \text{Principal} \times \left(\frac{\text{APR}}{12}\right) \]

  • Principal: $976.34
  • APR: 10.75% or 0.1075 as a decimal

Now substituting the values:

\[ \text{Interest}_{\text{credit card}} = 976.34 \times \left(\frac{0.1075}{12}\right) \]

Calculating:

\[ \text{Interest}_{\text{credit card}} = 976.34 \times 0.00895833 \approx 8.75 \]

Step 2: Calculate the interest earned in the savings account

The formula for the interest earned in a savings account for one month is similar:

\[ \text{Interest} = \text{Principal} \times \left(\frac{\text{APR}}{12}\right) \]

  • Principal: $100.00
  • APR: 2.75% or 0.0275 as a decimal

Now substituting the values:

\[ \text{Interest}_{\text{savings}} = 100.00 \times \left(\frac{0.0275}{12}\right) \]

Calculating:

\[ \text{Interest}_{\text{savings}} = 100.00 \times 0.00229167 \approx 0.23 \]

Step 3: Calculate the difference between the interest accrued and the interest earned

Now let's find the difference between the two amounts:

\[ \text{Difference} = \text{Interest}{\text{credit card}} - \text{Interest}{\text{savings}} \]

Substituting in the calculated values:

\[ \text{Difference} = 8.75 - 0.23 \approx 8.52 \]

Conclusion

The difference between the interest accrued by the credit card and what $100.00 would earn in a savings account over the span of one month is approximately $8.52.