A discounted note that pays $28000 in 6 months sells for X. Find X in each of the following interest rate scenarios:

a) simple interest at an annual rate of 7.5%

b) simple discount at anannualrate of 7.5%

c) compound interest at a nominal rate of 7.5% compounded semi-annually

d) compound interest at a nominal rate of 7.5% compounded monthly

e) Are any of your answers to the above exactly the same? If so, can you explain why?