Anna borrows $50, 000$ to the bank at a nominal interest rate $i(12) = 6\%$, (compounded monthly). She repays this loan by doing monthly payments (at the end of each month) during $6$ years. If each of the $36$ rst payments are of $R$ and each one of the last $36$ payments are of $(R + 1000)$. Using geometric series, determine $R$, and the interest amount that Anna paid to the bank.