theecko wrote:a car leaves south grapefruit at 9am and travels north at 35 mph. An hour later, a second car leaves from the same town and travels in the same direction as the first. It travels at 60 mph. How long will it be until the second car overtakes the first?
How far ahead is the first car when the second car starts? This is the distance to be "made up" on the first car. What is the net speed of the second car? That is, if you think of the first car as not moving and the second one moving toward it, how fast is the second one moving? How long will it take, at that speed, to make up that distance?