Carla and Vicki left the house at the same time and began traveling down the same road in the same direction. Carla drove at a speed of 60 mph and Vicki at a speed of 65 mph. How many hours was it before Vicki was 20 miles ahead of Carla?
You must know these 3 relationships:
1 - Distance = Time x rate(speed)
2 - Time =Distance / rate(speed)
3 - Rate(speed) =Distance / time.
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