Hey there! I'm happy to help!
3 hours is 180 minutes as there are 60 minutes in 1 hour. How many times does 30 minutes go into 180 minutes?
180/30=6
So, we have six of these 30 minute time slots that fit into 3 hours. So, we multiply our 37.5 miles by six to find the total mileage!
37.5×6=225
Caroline drove 225 miles.
Have a wonderful day! :D