The total cost of a firm is Rs 80 for 3 units of output, Rs 95 for 4 units of output, and Rs. 115 for 5 units of output. What is the marginal cost for the 5th unit of output?

Rs. 20.

The correct answer is Option (1) → Rs. 20.

Marginal Cost (MC) is the addition to total cost when one more unit of output is produced.

MC=TCn−TCn−1

Given:

• TC for 4 units = Rs 95

• TC for 5 units = Rs 115

$MC_5$ ​= 115−95 =20