1. A teacher grades 27 tests in 3 hours. Do these quantities (number of tests graded and time) vary directly or inversely?

2. It took Peter 3 hours to drive to his friend's home in Connecticut. He drove at an average speed of 54 mph. Do these quantities (time and speed) vary directly or inversely?

3. It took Peter 3 hours to drive to his friend's home in Connecticut. He drove at an average speed of 54 mph. Find the constant of variation.