The NPW of machine Y is
Machine X
$80,000
Benefits/year $12,000 for the first 10 years
Machine Y
$66,000
$9,000 per year for 20 years.
Initial cost
and $8,000 for the next 10
years
20 years
Salvage value $30,000
$20,000
MARR
10%
a) $13,478
b) $13,598
c) $12,457
d) $11,891