Answer:
A) Quantity, q = 5 units.
B) Revenue, r = $75.
Explanation:
The demand function for a product is
![p=30-3q](https://img.qammunity.org/2020/formulas/mathematics/high-school/db7zkdiv0bx9jv06lp6zitwqulhdj5vq6k.png)
where p is the price in dollars when q units are demanded.
Revenue = Price × Quantity
Using the given information, the revenue function is
![R=p* q](https://img.qammunity.org/2020/formulas/mathematics/high-school/3beatpexd5dkn4bfyr0j57q4a67w2xpiy6.png)
![R=(30-3q)* q](https://img.qammunity.org/2020/formulas/mathematics/high-school/snwpyebd0jcm7dyqewv2g0g41jcesjx01c.png)
.... (1)
Differentiate with respect to q.
![(dR)/(dq)=30(1)-3(2q)](https://img.qammunity.org/2020/formulas/mathematics/high-school/18tpbh8jud64yjnpgpaleupxkw5bp3x98t.png)
![(dR)/(dq)=30-6q](https://img.qammunity.org/2020/formulas/mathematics/high-school/dedibkmyrbbjyspilyun6m1lwuqd868rcq.png)
Equate
to find the critical value of q.
![30-6q=0](https://img.qammunity.org/2020/formulas/mathematics/high-school/3ox4xfbskouijbso48qejrh6mcl018h436.png)
![30=6q](https://img.qammunity.org/2020/formulas/mathematics/high-school/z6qf27jfb9oc9ibfdttxteb1rptlzm68ur.png)
Divide both sides by q.
![5=q](https://img.qammunity.org/2020/formulas/mathematics/high-school/wqc2pz1urtv9c8t2efvtnaf9948vopwz9x.png)
The value of q is 5.
Differentiate
with respect to q.
![(d^2R)/(dq^2)=-6>0](https://img.qammunity.org/2020/formulas/mathematics/high-school/4tnxau9w25q4a7looxadnnj58gn8d4kg7p.png)
So, the revenue function is maximum at q=5.
Substitute q=5 in equation (1).
Therefore, the level of production that maximizes the total revenue is 5 units and the revenue is $75.