A loan of $39,999.85 is to be repaid by payments at the end of each quarter for eight years. Each payment is 2% higher than its predecessor. The loan is made at a nominal rate of discount of 4% payable quarterly. Find the balance just after the 20th payment, the amount of interest in the twentieth payment, and the amount of principal in the twentieth payment. (Answer: The balance just after the 20th payment is $20,147.74, the interest in the 20th payment is $217.23, and principal in the 20th payment is $1357.73. and Note that it is a rate of discount, not interest)