To determine the interest rate Jeff is charging you, we can treat this as a problem involving the present value of an annuity. You are making regular payments of $750 every month, and the total amount paid over the three years must equal the $29,000 debt.

We can use the formula for the present value of an annuity due (since the first payment is made today) to solve for the interest rate. The formula for the present value of an annuity due is:

$PV = P \times \frac{1 - (1 + r)^{-n}}{r} \times (1 + r)$

Where:

• $PV$ is the present value (the amount of the debt, which is $29,000),
• $P$ is the periodic payment ($750),
• $r$ is the interest rate per period (monthly in this case),
• $n$ is the total number of payments (since you are making two payments per month for 3 years, that is $2 \times 12 \times 3 = 72$ payments).

Now, we need to solve for the interest rate $r$.

Step-by-step approach:

1. Rearrange the formula to isolate $r$.
2. Use trial and error or a numerical method (such as a financial calculator or Excel) to solve for the interest rate, since the formula cannot be easily solved algebraically.

Alternatively, since this involves an interest rate calculation, we can use Excel's RATE function, or the financial calculator to compute the interest rate directly.

The Excel formula would look like this:

=RATE(72, -750, 29000) * 12

This formula gives the annual interest rate. Let's calculate the interest rate to get the exact value. Would you like me to proceed with that, or do you prefer an explanation of how this approach works in detail?