Classify the following costs as either variable, fixed, or mixed costs:

1. Rent for a factory building
2. Direct labor for manufacturing
3. Raw materials used in production
4. Sales commission for each unit sold

Company B wants to achieve a target profit of $50,000. Given a selling price of $100 per unit, variable costs of $60 per unit, and fixed costs of $40,000, calculate the number of units the company needs to sell to reach the target profit