Let's solve the questions step by step:

(a) Greg runs 9 miles in 82 minutes. How many miles does he run per minute?

To calculate miles per minute, divide the total miles by the total minutes:

$\text{Miles per minute} = \frac{\text{Total miles}}{\text{Total minutes}} = \frac{9}{82}$

$\text{Miles per minute} = 0.1098 \, \text{(rounded to 0.11 miles per minute)}$

(b) Keller's Bike Rentals charges $19 to rent a bike for 5 hours. How many dollars does it cost per hour of bike use?

To calculate dollars per hour, divide the total cost by the total hours:

$\text{Dollars per hour} = \frac{\text{Total cost}}{\text{Total hours}} = \frac{19}{5}$

\text{Dollars per hour} = 3.8 \, \text{(rounded to $3.80 per hour)}

Final Answers:

(a) 0.11 miles per minute
(b) $3.80 per hour

Would you like further clarification or detailed steps?

Related Questions:

1. How long would it take Greg to run 15 miles at the same rate?
2. If the bike rental cost was $24 for 6 hours, how much would it cost per hour?
3. How many miles can Greg run in 200 minutes at his current speed?
4. What would be the total cost of renting a bike for 10 hours at Keller's Bike Rentals?
5. If Greg increases his speed by 20%, how many miles would he run in 82 minutes?

Tip: For unit conversions or rates, always divide the total quantity by the total time or duration.