SOLUTION: Two cars start together and travel in opposite directions. At the end of 4 hours, the cars are 656 km apart. If one car travels 20 km per hour faster than the other, find the spee

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Question 761613: Two cars start together and travel in opposite directions. At the end of 4 hours, the cars are 656 km apart. If one car travels 20 km per hour faster than the other, find the speed of each car.
Distance problems are confusing. Can you please tell me how to solve this? Thank you.
Answer by ramkikk66(644) About Me  (Show Source):
You can put this solution on YOUR website!
Let speed of slower car be x km / hour
Then speed of faster car is x+20 km/hour
At the end of one hour, car 1 would have travelled x km, and car 2 (x+20) km, but in opposite directions.
Hence the distance between them would be x%2Bx%2B20+=+2x%2B20 km.
Every hour, the distance between them increases by 2x+20.
At the end of 4 hours the distance would be
4*(2x+20) which is given to be 656. So we get the equation
4%2A%282x%2B20%29+=+656 or 8%2Ax+%2B+80+=+656
Simplifying
8%2Ax+=+656+-+80+=+576
x+=+576%2F8+=+72
So, Car 1 is travelling at 72 Kmph and car2 at 92 Kmph.
:)