Answer:
1. **Direct Variation:** The more hours you work, the higher your paycheck will be. (Direct relationship between work hours and earnings)
2. **Indirect Variation:** As the price of gas increases, the number of miles people choose to drive decreases. (Inverse relationship between gas prices and driving distance)
3. **Joint Variation:** The total cost of a meal at a restaurant depends on the number of people (direct) and the cost per person (direct). More people and a higher cost per person both contribute to an increase in the total bill.