Final answer:
To find Irene's speed in miles per minute, divide the distance she traveled by the time it took her.
Step-by-step explanation:
In order to find Irene's speed in miles per minute, we need to divide the distance she traveled by the time it took her. Since the distance is given in miles and the time is given in minutes, the resulting value will be in miles per minute.
Speed = Distance / Time
Speed = 12 miles / 45 minutes
Speed = 0.267 miles per minute