SOLUTION: Two cars, one traveling 12 mph faster-than the other, start at the same time from the same point and travel in opposite directions. In four hours they are 384 mi apart. Find the ra

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Question 229979: Two cars, one traveling 12 mph faster-than the other, start at the same time from the same point and travel in opposite directions. In four hours they are 384 mi apart. Find the rate of each car.
Answer by drj(1380) (Show Source):
You can put this solution on YOUR website!
Two cars, one traveling 12 mph faster-than the other, start at the same time from the same point and travel in opposite directions. In four hours they are 384 mi apart. Find the rate of each car.

Step 1. Let x be the speed of one car

Step 2. Let x+12 be the speed of the other car since it is traveling 12 mph faster than the other.

Step 3. We note that distance = speed * time.

Step 4. Let 4x be the distance traveling the car in Step 1 after 4 hours.

Step 5. Let 4(x+12) be the speed of the other car in Step 2 after 4 hours.

Step 6. Then, 4x+4x+48=384 since they will be 384 miles apart.

Step 7. Solving the equation in Step 6 yields the following

Subtract 48 from both sides of the equation

Divide by 8 to both sides of the equation

and

4*(42+54)=384 where both cars traveled for 4 hours for a total distance of 384 miles...so it check out.

Step 8. ANSWER: One car traveled at 42 mph and the other car traveled at 54 mph.

I hope the above steps were helpful.

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Respectfully,
Dr J
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