computing net present value $($NPV$)$ and internal rate of return $($IRR$)$ A firm has the following investment alternatives:

Cash Inflows

Year A B C

$1$ $$400$ $$---$ $$---$

$2400400---$

$3400800---$

$44008001,800$

Each investment costs $$1,400,$ and the firm's cost of capital is $10$ percent.

a$.$ What is each investment's internal rate of return?

b$.$ Should the firm make any of these investments?

c$.$ What is each investment's net present value?

d$.$ Should the firm make any of these investments?