Question 1112541
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There are all kinds of variations on how to solve a problem like this; so far you have received two good answers from other tutors.<br>
Here is a way I like to solve problems like this; for me the required thought process and the required arithmetic is a bit easier than other methods.  Try this method and see if it "works" for you.<br>
The distances going and returning are the same; so if the ratio of times is 10:7 then the ratio of speed is 7:10.  Since the higher speed is 18mph higher than the lower,
{{{7/10 = x/(x+18)}}}
{{{10x = 7x+126}}}
{{{3x = 126}}}
{{{x = 42}}}<br>
The lower speed is 42mph; the higher speed is 42+18 = 60mph.<br>
The question asks how far Felipe lives from the mountains; you can find that distance either with 42*10 = 420 or with 60*7 = 420.