How do I find the present value of investment costs each year

Question

1. How do I find the present value of investment costs each year and
2. how is it different from present value of operation and maintenance costs?

Here is my problem in more detail, according to the investment costs year 0 = \$$12$

year 1 = \$$8$

year 2 = \$$7$

and year 3 = \$$6$

so how am I supposed to find the present value of investment costs each year at a discount rate of $8$%?

And how is that different from present value of operations and maintenance costs at the same rate???

Answer 1

It is the same as operations and maintenance costs. A cost of $i\$$ in $n$ years is the same as $\frac{i}{1.08^n}\$$ today.