A point on the graph (for train b) that is exact is (2,250). From the origin, the rise is 250 and the run is 2. Rise/run would give us 250/2, which is 125. This means that train B travels 125mi every hour. For train A, we subtract the distance from hour 2 from hour 3 to get the miles per hour (because 3-2=1, subtracting the distance of hour 3 from 2 will give us the distance in 1 hour). 180-120= 60, meaning train A travels at 60mph. 60<125, meaning A