A courier rides his scooter 15 km towards the North, then 12 km towards the West and then 6 km towards the South. What is the shortest distance between the courier and his starting point?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 15 km
Keep a running total of the distance east (or west) and north (or south) of the start; when both are left over, the shortest distance is the hypotenuse of a right triangle.
15 km North: 15 km north of the start
12 km West: 15 km north, 12 km west
6 km South: \(15-6=9\) km north, 12 km west
Shortest distance \(=\sqrt{12^{2}+9^{2}}=\sqrt{144+81}=\sqrt{225}=15\) km
The shortest distance is 15 km.
