The demand function for a certain product is represented by the equation: \(p = 20 + 5x - 3x^2\), where \(x\) is the number of units demanded and \(p\) is the price per unit (in Rs.), then the marginal revenue when 2 units are sold, is:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Rs. 4
Total revenue is price × quantity:
\(R = px = x(20 + 5x - 3x^2)\)
\(R = 20x + 5x^2 - 3x^3\)
Marginal revenue is the derivative of R with respect to x:
\( \displaystyle MR = \frac{dR}{dx} = 20 + 10x - 9x^2 \)
At \(x = 2\):
\(MR = 20 + 20 - 36 = 4\)
So the marginal revenue is Rs. 4.
CBSE Applied Mathematics (Class XII):
Marginal Cost and Marginal Revenue
