It took Vaughn 3 hours to drive to his sister's house. He took the same route on the way back home, but this time the trip took only 2.5 hours. If Vaughn drove 10 mph faster on his return trip, how fast did he drive on his way to his sister's house?
Distance to and from are the same = d
speed to sis = x
speed from sis = x+10 m/hr
rate x time = d
3 hrs * x m/r = 2.5 hr (x+10)
3x = 2.5x + 25
.5x = 25 You can take it from here !