Question 106385This question is from textbook Elementary and Intermediate Algebra
: A jet flew at an average speed of 640 mph from Los Angeles to Chicago. Because of head winds the jet averaged only 512 mph on the return trip, and the return trip took 48 minutes longer. How many hours was the flight from Chicago to Los Angeles? How far is it from Chicago to Los Angeles?
This question is from textbook Elementary and Intermediate Algebra
Answer by solver91311(24713)   (Show Source):
You can put this solution on YOUR website! This problem depends on the relationship between distance, rate, and time. The formula for straight line travel is:
What we don't know is the time, t or the distance, d. But we can say that the distance from Los Angeles to Chicago is:
We can also say that the distance from Chicago to Los Angeles is given by:
since the return trip took 48 minutes longer.
The distance between the cities remains constant regardless of the direction of travel, so we can say:
Solving:
Therefore the elapsed time for the Los Angeles to Chicago trip was 192 minutes, and the elapsed time for the Chicago to Los Angeles trip was 48 minutes longer, or 240 minutes, or 4 hours.
Now that we know the time value for each of the rates, we can use the same formula to calculate the remaining variable, d.
To check the answer:
Which just goes to prove that no one picked Los Angeles up and moved it while you were visiting Chicago.
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