The Gotham Township Police Department has 5 patrol cars. A patrol car breaks down and requires service once every 30 days. The police department has two repair workers, each of whom takes an average of 3 days to repair a car. Breakdown times and repair times are exponential.

1 Determine the average number of police cars in good condition.

2 Find the average down time for a police car that needs repairs.

3 Find the fraction of the time a particular repair worker is idle.