Question 37901
Let the distance be x:
Equation:
{{{x/9+x/6=2.5}}}
Mutliply the whole equation by 18
{{{18(x/9)+18(x/6)=18(2.5/1)}}}
2x+3x=45
x=9

or you can do it like this:
9t=6(2.5-t)
t=1
9(1)=9
Hence, the runner runs 9 miles.
Paul.