CA Foundation P3 · Chapter 8 · Question 3 of 9
The total cost function of a firm is C = 0.5x² + 20x + 400 (in ₹). The marginal cost when x = 30 units is:
Test yourself: pick an answer
Reveal answer & explanation
Correct answer: A) ₹50
Explanation
MC = dC/dx = x + 20. At x = 30, MC = 30 + 20 = ₹50. ₹1,450 is the total cost (450 + 600 + 400), ₹48.33 is the average cost (1,450/30), and ₹35 forgets to differentiate 0.5x² correctly.
More Basic Applications of Differential and Integral Calculus in Business and Economics MCQs
- Q5The profit function of a firm is P = −2x² + 120x − 500 (in ₹). The maximum profit is:
- Q6∫(6x² − 4x + 5) dx is equal to:
- Q7The value of the definite integral ∫ from 1 to 3 of (2x + 1) dx is:
- Q8The demand function for a product is q = 100 − 2p. The price elasticity of demand (in absolute value) at p = 20 is:
- Q9The marginal revenue function of a firm is MR = 50 − 4x. The corresponding demand (average revenue) function is: