Question 1134839
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The method you are using -- multiplying the given measurement by unit fractions to convert the units without changing the measurement -- is a perfectly good way to work problems like this; in some similar problems where the units are unfamiliar, it is by far the easiest method to use.<br>
But you have to use the correct unit fractions....<br><pre>
   4500m    1 hr    3.28 ft   49.2 ft
   ----- * ------ * ------- = -------
    5 hr   60 min     1 m      1 min</pre>
(1 meter = 3.28 feet, not 5280 feet)<br><pre>
   4500m    1 hr     1 min    1 km    2.5*10^(-4) km
   ----- * ------ * ------ * ------ = --------------
   5 hr    60 min   60 sec   1000 m        1 sec</pre>
(1 km is 1000 meters; not the other way around)<br>
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Added in response to the post from tutor @ikleyn, in response to this response from me....<br>
Dear tutor @ikleyn....<br>
Why do you have to think the way you work problems is right?!<br>
What about the method of unit fractions leads to errors?  The only way to make an error with that method is to use it improperly.  The same can be said of any other method for solving this kind of problem, or any kind of problem.<br>
What in my response "confirms" that the method of unit fractions leads to errors?  My results are more accurate than the "correct" answers given in the posted problem.<br>
I too have a huge amount of experience in performing unit conversions; and I also have a huge amount of experience seeing students performing unit conversions.  In my working with students, the method of unit conversions is far more successful than any other.<br>
Please keep to your usually excellent responses to questions, and stop criticizing other responses from other tutors just because they don't agree with the way you do things.