For a better understanding of the solution provided here please go through the diagram shown in the file that has been attached.
Aaron starts at O, goes due south for 50 meters, turns left at A, faces due east, goes 70 meters in that direction, turns left at B and heads back north. Goes 50 meters due north and reaches the point C which lies exactly 70 meters to the east of where Aaron had first started from (that is, point O). Aaron then turns right, that is, faces exact east and continues for 60 miles till he reaches point D.
Thus, Aaron's final location is a total distance of OC+CD in the due east direction.
Now, as can be clearly seen from the diagram, OC=AB=70 meters.
Therefore, Aaron's final location is (70+60)=130 meters due east from the starting point.