SOLUTION: Please help with this distance problem. Two cars start at an interstate interchange and travel in the same direction at average speeds of 40 mph and 55 mph. how much time must e

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Question 43449This question is from textbook College Algebra
: Please help with this distance problem.
Two cars start at an interstate interchange and travel in the same direction at average speeds of 40 mph and 55 mph. how much time must elapse before the two cars are 5 miles apart?
i know the distance formula d=r*t, but i dont know how to put the numbers in the correct order.
thank you in advance for the help This question is from textbook College Algebra

Answer by psbhowmick(878) About Me  (Show Source):
You can put this solution on YOUR website!
Speed of 1st car is 40 mph. This means in 1 hr. it travels 40 miles.
Speed of 2nd car is 55 mph. This means in 1 hr. it travels 55 miles.
So after 1 hr. the distance between them will be (55 - 40) = 15 miles.

In other way, the distance between the cars will be 15 miles after 1 hour.
So, the distance between the cars will be 1 mile after 1%2F15 hour.
So, the distance between the cars will be 5 miles after %281%2F15%295+=+1%2F3 hour.

So the cars will be 5 miles apart after 1%2F3 hour i.e. 20 mins.