Mixed or semi-variable cost:
A cost that has the characteristics of both variable and fixed cost is called mixed or semi-variable cost. For example, the rental charges of a machine might include $500 per month plus $5 per hour of use. The $500 per month is a fixed cost and $5 per hour is a variable cost. Another example of mixed or semi-variable cost is electricity bill. The electricity bill can be divided into two parts – (1) line rent and (2) cost of units consumed. The line rent is not affected by the consumption of electricity whereas the cost of units consumed varies with the change in units consumed.