a) Total fixed cost refers to the cost which remains constant irrespective to the level of output, the total fixed cost will never change. For example, suppose Mr X hired a shop at a dent of rupees 500 per month for selling grocery, during first month he keeps a shop closed even then he will have to pay the rent so rent is fixed cost.

Let’s understand it with help of following cost schedule and graph

Cost Schedule

Graph

b) Total variable cost is the cost of the variable inputs employed by the firm which is directly proportional to the level of change in the output. It becomes zero when the level of output is zero, increases with output, decreases with output.

Let’s understand it with help of following cost schedule and graph

Cost Schedule

c) Total cost is the sum of total fixed cost and total variable cost. At zero level of output total cost will be just the fixed cost.

Let’s understand it with help of following cost schedule and graph

Cost Schedule

Graph