If total cost of producing 7^th and 8^th unit of goods are Rs. 624 and Rs. 727 respectively, find marginal cost of producing 8^th unit of goods.

The marginal cost (MC) of producing the $8^{\text{th}}$ unit is calculated as the difference between the total cost (TC) of producing 8 units and the total cost of producing 7 units.

Given:

• Total cost of 7 units = Rs. 624
• Total cost of 8 units = Rs. 727

$$\text{MC}={\text{TC}}_8-{\text{TC}}_7$$

$$\text{MC}=727-624=103$$

Thus, the marginal cost of producing the $8^{\text{th}}$ unit of goods is Rs. 103.