The average cost of making $x$ units is $2x + 5 + \frac{100}{x}$ rupees. What is the marginal cost when 10 units are made?

Explanation

1. 01

   Total cost $= x \times$ average cost $= 2x^{2} + 5x + 100$.

2. 02

   $MC = 4x + 5$, so at $x = 10$ it is 45 rupees.