Margo borrows 400.00 agreeing to pay it back with 6% annual interest after 10 months. How much interest will she pay

1. Convert the annual interest rate into a decimal:
r = 6\% = 0.06

2. Convert the time Margo will borrow the money into years:
t = \frac{10}{12} \text{ years}

3. Plug the values into the simple interest formula:
I = 400 \cdot 0.06 \cdot \frac{10}{12}

4. Calculate the interest:
I = 20

Therefore, Margo will pay $20 in interest.