two methods can be used for producing expansion anchors.  Method A
costs $80000 initially and will have a $15000 salvage value after 3
years.  The operating cos with this method will be $30000 per year. 
Method B will have a first cost of  $120000, an operating cost of
$8000 per year, and a $40000 salvage vale after its 3-year life.  At
an interest rate of 12% per year, which method should be used on the
basis of a present worth analysis? (Please add in cash flow diagram)