Final answer:
Dr. Gale's running speed is 2 km/hr, calculated by dividing the distance of 3 km by the time of 1.5 hours, making Option 1 the correct choice.
Step-by-step explanation:
To determine Dr. Gale's speed in km/hr, we need to convert the time she runs into hours and then use the formula for speed, which is distance divided by time. She runs 3 km in 90 minutes, which is 1.5 hours (since 90 minutes is 1.5 times 60 minutes, and there are 60 minutes in an hour).
To find her speed, we divide the distance by the time:
- Speed = Distance / Time
- Speed = 3 km / 1.5 hr
- Speed = 2 km/hr
Therefore, her speed is 2 km/hr, which corresponds with Option 1.
This calculation is also reasonable when considering that if Dr. Gale were to run for a full hour at this pace, she would cover approximately 2 km, as 1.5 hours is to 3 km.