The cost function for a product in a firm is given by 5q^2, where q is the amount of production. The firm can sell the product at a market price of 50 per unit. The number of units to be produced by the firm such that the profit is maximized is: A. 5 B. 10 C. 15 D. 25

GATE 2012 · General Aptitude · Cost Market Price · medium

Answer: The firm should produce 5 units to maximize profit (pi_max = Rs.125).

  1. Write the Profit Function: pi(q) = 50q - 5q^2
  2. Differentiate and Set Equal to Zero: 50 - 10q = 0 => q = 50/10 = 5
  3. Confirm it is a Maximum: Second derivative = -10, which is negative, confirming q = 5 is a maximum.