An investment offers cash flows of $300, -$200, -$125 each year 
            starting at time zero. What is the net present value of this 
            investment if the market rate of interest is 15%?

Hi again fatima!
In order to answer this, you would need to use the same formula I
provided in the previous question I answered for you (Question ID
566664), found in the link:

Calculating the Present and Future Value of Annuities
http://www.investopedia.com/articles/03/101503.asp


In this case, the present value of this investment can be calculated as:

PV = 300 + (-200)/1.15 + (-125)/1.15^2

Notice that the first payment is not discounted, because according to
your question, it's done today. The -$200 payment is made one year
from now; and the $-125 one is made two years from now. The formula
above gives that the present value of this investment is $31.56.


I hope this helps!
Best wishes,
elmarto