Answer:
q = 20
P = 120
Step-by-step explanation:
![\left \{ {{C = 1.5Q^(2) +40Q + 100} \atop {p = 140 - 1Q}} \right.](https://img.qammunity.org/2020/formulas/business/college/5twy559u2wdewyon23bfwnv5tboz9g17w7.png)
From the Price formula, we deduce that total revenue and from there, the marginal revenue
Total revenue = Price x Q
Total revenue = (140 - 1Q) x Q
Total revenue = 140Q - 1Q^2
Now marginal revenue will be dTR/dQ'
marginal revenue = 140 - 2Q
Now we solve for marginal cost:
Total Cost 1.5Q^2 +40Q + 100
We calculate dTC/dQ'
Marginal Cost = 3Q + 40
Now we do MR = MC
140 - 2Q = 3Q + 40
100 = 5Q
Q = 20
Price= 140 - 1Q = 140 - 1 x (20) = 120
The profit-maximizing Q is 20 and P equal to 120
We can try to check:
Total Revenue = $121 x 19Q = 2,299
Total Revenue = $120 x 20Q = 2,400
Total Revenue = $119 x 21Q = 2,499
Total Cost 1.5Q^2 +40Q + 100
Q = 19 TC = 1401.5
Q = 20 TC = 1500
Q = 21 TC = 1601.5
Profit:
at Q 19 2,299 - 1,401.5 = 897.5
at Q 20 2,400 -1,500 = 900
at Q 21 2,499 - 1,601.5 = 897,5
At Q = 20 the profit is maximize From there, adding a new unit decrease the profti for the company.