Answer:
$36,000 increase
Explanation:
For computing the increase or decrease in income, first we have to determine the net cash outflow which is shown below:
Net cash outflow = Purchase of new spotter truck - sale value of old truck
= $120,000 - $31,000
= $89,000
Now the increase or decrease would be
= Variable manufacturing cost for five years - net cash outflow
= $25,000 × 5 years - $89,000
= $125,000 - $89,000
= $36,000 increase