11. Interestingly, the interest is not divided up evenly among the 60 payments. For the first payment, you will pay one month's worth of interest on the entire $20,000 calculated using the simple interest formula I Prt. Find the interest portion of the first payment. 11. Interestingly, the interest is not divided up evenly among the 60 payments. For the first payment, you will pay one month's worth of interest on the entire $20,000 calculated using the simple interest formula I Prt. Find the interest portion of the first payment