Question 1016647: If car takes 30min to travel 10 miles,what is the speed of car in miles per hour?
Found 3 solutions by josmiceli, FrankM, fractalier:
Answer by josmiceli(19441)   (Show Source):
Answer by FrankM(1040)  (Show Source):
You can put this solution on YOUR website! We have  and wish to convert to 
up top, the numerator, we are all set. To cancel min in the denominator, and replace with hours, we will multiply by  but specifically  as that's the ratio between these units.
Note, this process is called dimensional analysis, and can be used for a long chain of calculations. Say, feet/second to miles per year, for example. The setup is important because it keeps the units correct. Multiply by 1hr/60min above, by mistake, and you'll see minutes don't cancel, but you have hr^2 in the denominator. Pay attention to the units, and you won't make that mistake.
Answer by fractalier(6550)  (Show Source):
You can put this solution on YOUR website! You can reason this one out without doing much math...
Think about it...if you can go 10 miles in half an hour, how far can you go in an hour?
Twice as far, right? Thus 20 miles per hour...
Sometimes the math gets in the way of better reasoning...
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