Question 1128494: I did this wrong twice and I am on my final chance to get it right; can someone please assist. Thank you.
A car travels 560 mi averaging a certain speed. If the car had gone 10 mph faster, the trip would have taken 1 hr less. Find the car's average speed.
Found 2 solutions by ikleyn, greenestamps: Answer by ikleyn(52780) (Show Source): Answer by greenestamps(13200) (Show Source):
You can put this solution on YOUR website!
Apparently this question is from a course you are taking. Our giving you the answer won't help you learn anything; and presumably learning something is your objective in taking the course.
It would help us help you if, as you are asked to when you post your question, you told us what you tried to do on the problem.
Algebraically, if x is the car's speed, then the number of hours taken to drive 560 miles is 560/x. The number of hours to travel the same 560 miles at a speed 10mph faster would be 560/(x+10). And the second time is 1 hour less than the first:

Multiply through by the least common denominator of all the fractions, x(x+10):



Factor into the form (x+?)(x-?) to finish the problem.
I hope you have learned enough from the course that you can do that....
If you can't finish, then try finding the answer by logical guess-and-check. Presumably this is a computer based question, and only an answer is needed; it doesn't matter how you get the answer. (Well... if you want to learn from the course, it matters; but if you just need the right answer, you can guess it.)
You need two numbers -- a reasonable highway speed in mph and a reasonable number of hours -- whose product is 560. Then you need another speed 10mph faster and another number of hours that is 1 less, whose product is again 560.
A little playing with "nice" numbers should allow you to guess the answer to the problem.
|
|
|