To calculate the distance traveled by the car, we need to convert the time from minutes to hours since the speed is given in miles per hour (mph). There are 60 minutes in an hour, so 45 minutes is equal to 45/60 = 0.75 hours.
Now, we can use the formula:
Distance = Speed × Time
Plugging in the values:
Distance = 40 mph × 0.75 hours
Distance = 30 miles
Therefore, the car will travel 30 miles in 45 minutes at a constant speed of 40 mph.