Final answer:
Abby will need to pay back the principal amount of $3,000 plus the interest accrued of $146.23, for a total of $3,146.23 on January 29.
Step-by-step explanation:
To calculate the amount Abby will pay on January 29, we need to find the interest accrued on the loan from September 10 to January 29.
First, we need to calculate the number of days Abby had the loan. From September 10 to January 29, there are 141 days.
Next, we need to calculate the interest accrued. The interest rate is 12¾% or 12.75%.
Using the formula: Interest = Principal x Rate x Time, we can calculate the interest accrued:
Interest = $3,000 x 0.1275 x (141/365) = $146.23
Abby will need to pay back the principal amount of $3,000 plus the interest accrued of $146.23, for a total of $3,146.23 on January 29.