Suppose we know the following values for a demand function, $p(q),$ for a product where $p$ is the price pe unit and $q$ is the number of units demanded:

When the demand is $140$ units, the price is $$\frac{138}{?}$ unit and the price is decreasing by $$\frac{0\mathrm{.}50}{?}$ unit for each additional unit demanded.

The cost for making $q$ units is given by: $C(q)=8q$

a$.$ Calculate the revenue when $140$ units are sold: $$ dollars

b$.$ Calculate the marginal revenue when $140$ units are sold: $$ dollars$/$unit

c$.$ Calculate the profit when $140$ units are sold: $$ dollars

d$.$ Calculate the marginal profit when $140$ units are sold: $$ dollars$/$unit