Answer:
Conversion gives 42,107 km in total 
Explanation: 
A marathon covers 26 miles and 285 yards. 
If 1 kilometer is 0.6214 miles, then how many kilometers are 26 miles, then: 
1 km = 0.6214 miles 
X = 26 miles 
X = 41,841 km 
Now if 1 yard is 36 inches, how many inches is 285 yards? 
1 yard = 36 inches 
285 yards = X 
X = 10260 inches 
If an inch is equal to 2.54 cm, how many centimeters are 10260 inches? 
1 inch = 2.54 cm 
10260 cm = X 
X = 26060.4 cm 
And 26060.4 cm is 0.260604 km 
Finally, the sum of the distance would be:
41.841 km + 0.260604 km = 42.107 km