Three machines are considered for a manufacturing operation. The cash flows shown black ( all in thousands )

Machine A.       Machine B.   Machine C.
initial cost
160.                        33.                    44.

Annual revenue
27.                          22.                    13

annual maintenance costs
     6.                           9.                    4
salvage value
11.                              8.                    3

useful life ln years
infinity                         3.                   7

a) Draw cash flow diagram for each machine?

b) which machine is preferable on the basis of annual worths analysis i= 10%

( assume the selected alternative wi) be repeated each life cycle, in exactly the same manner)