2. The repayment interest in the second year is: 24,000 * 4.90% =1176 yuan (calculated from February 20th of last year to February 20th of that year).
3. The repayment interest in the third year is: 24,000 * 4.90% =1/76 yuan (the principal has not been repaid in the first two years, so the interest does not become 1572 yuan, and the principal needs to be repaid at the same time in the third year: 24,000/2 =12,000 yuan.
4. The repayment interest of the fourth year is:12000 * 275 * 4.90%/360 = 449.16 yuan (because the repayment date of the last year is set as September 20th, the loan interest of the last year is actually less than one year, so the actual number of days from February 20th to September 20th is/kloc.