If we invest 500 in our mushroom stand, expecting a 2% monthly return rate, every month, for 3 years, how much is our investment worth at the end of the term. Also calculate how much interest we earn. Start with identifying if we are calculating Future Value, or Present Value. Future value Net present value Rt NPV = t=0 (1+i) F = P(1+r)t Present value Fu (1+r)t Pv