simple interest formula: A = P(1 + rt) where P is the Principal amount of money to be invested at an Interest Rate R% per period for t Number of Time Periods.
Easy, right? P = 8000 r=3.5. t=8.
Just plug it into the formula.
For compounding, the formula changes just a bit, n = the number of times that interest is compounded per unit t. So in this problem, compounding annually, n=12
Compounded interest only (without principal): P (1 + r/n) (nt) - P
For continuous,it’s compounded on the initial principal as well as all interest earned, so the principal will receive interest continously.
Is it a take home? If you feel desperate I can try to help you at a low rate. Finance isn’t in my profile but I did my Masters at Columbia in international finance, And I worked in an investment bank. This looks very basic so I think I can help you.