Kristin is driving 60 miles per hour. Kristin is 20 miles behind a truck that is driving 50 miles per hour. How long will it take her to catch up to the truck? How far will she go in that time?

Question

mrnood · Answer

How much faster than the truck is sh travelling?

If the truck was stopped and she travelled at the same DIFFERENCE in speed - then the answer is the same....(for how long it would take)

then use that time @ 60 mph for how far she travelled

mrnood · Answer

How much faster than the truck is she travelling?

anonymous · Answer

She is driving 10 miles and hour faster. @MrNood 
So in one hour she will have gone 10 miles farther than the truck. The truck is already 20 miles ahead of her. So the truck goes 70 miles away from her counting the distance it already has. Then she catches up by 60 miles. Then there is a difference of 10 miles. Then the truck goes 50 miles forward and she goes 60 miles. So it takes two hours.

anonymous · Answer

So she will go 120 miles in that time.

mrnood · Answer

Yes - that's correct - well done