the mathematical answer is w, which is an algebraic number meaning ''who cares?''
I'm guessing you don't like Maths...
As tony_montana said, the answer is 4 minutes
Although I didn't see the answer until after I did it myself. I missed page 3 for some reason and only saw Lucky Maroon's post on page 4.
My working:
time= distance/speed
For Dewey:
t+2=x/0.08
(where t= time to catch up and x= distance they ran)
0.08t+0.16=x
For Malcolm and Reese:
t=x/0.12
0.12t=x
So:
0.12t=0.08t+0.16
0.04t=0.16
t=0.16/0.04=4 minutes
(Which means incidentally they ran 0.12*4=0.48 miles
which is around 772.5 metres)