.
Let "d" be the distance to the school.
Then the time in the first scenario is hours.
The time in the second scenario is hours.
The difference is 15 minutes, or of an hour :
It gives you this "time" equation
- = .
Multiply both sides by 36 to rid off the denominators.
You will get
6d - 4d = 9
2d = 9
d = 9/2 = 4.5 miles.
ANSWER. The distance to the school is 4.5 miles.
CHECK. a) = of an hour;
b) = of an hour.
The difference is - = of an hour. ! Correct !
Solved.
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Look into the lesson
- How far do you live from school?
in this forum.
And find there the exact analogue (TWIN problem) to yours.