A person is on a car trip Let d be the distance in miles traveled in t hours of driving The line in the figure describes the relationship between t and d a Is the car traveling at a constant speed b What is the speed of the car dA Miles 300 240 180 120 60 0 0 1 2 Hours 3 4 a Is the car traveling at a constant speed Yes O No b What is the speed of the car mph The speed of the car is Type a whole number