Answer: Lionel makes a profit of $5 on his shrub trimming service alone. This will add to a profit of $10 he earns on his standard service. Hence Lionel should continue offering the shrub trimming service.
Lionel makes a profit of
on his standard service
The revenue earned from offering shrub trimming also is $40.
The additional revenue earned from shrub trimming is

The additional cost of shrub trimming is $10.
So, the profit earned on the shrub trimming service is
