Why would a company issue a bond below the stated interest rate? What is the term used for monies that represent the difference in the stated rate and the market rate? What if a bond is issued above the market rate what is that difference called?

Chang, Inc. issued a 3-month note in the amount of $360,000 on 12/01/17 with an annual rate of 5%. What amount of interest has accrued as of 12/31/17?