You run at a pace of 8.5 minutes per mile in a 26.2 mile marathon. how many minutes will it take finish?

8.5 minutes per mile is equivalent to 

17 minutes

  2 miles

and the reciprocal of that is

2 miles

17 min

Now multiply 26.2 miles by 

17 min                                   (17 min)* (26.2 mi)
,    obtaining        
 2 miles                                           2 mi

This simplifies to (17)(26.2)/2 minutes = 222.7 minutes, 

or

222.7 minutes        1 hr
* = 3.7 hours
          1                  60 min