On a certain day John decided to go school using his newly purchased skates. So, he left his house and skated 15 km northwards, then turned left and skated 7 km, then he took another left turn and skated 15 km, and then finally turned right and skated 13 km. How far exactly is his school from his house?
A. 20 km
B. 6 km
C. 2 km
D. 28 km
Sol:
