Question 1208126
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The other tutor shows the setup for a typical formal algebraic solution.<br>
Here is a very different way to set up and solve the problem -- which I personally find much easier and faster than the formal algebraic method.<br>
The distances to and from the repair shop are the same; therefore, since the ratio of speeds is 6:20 = 3:10, the ratio of times at the two speeds is 10:3.<br>
Let 10x = time (minutes) at 6mph
let 3x = time at 20mph
The total time is 39 minutes:
10x+3x = 39
13x = 39
x=3
10x = 30 = time at 6mph
3x = 9 = time at 20mph<br>
(or perhaps you can do the preceding calculation mentally -- 39 minutes in the ratio 10:3 means 30 minutes and 9 minutes....)<br>
She spent 30 minutes = 1/2 hour walking to the repair shop at 6mph.  So the distance from her home to the repair shop is 6(1/2) = 3 miles.<br>
ANSWER: 3 miles<br>