A delivery van leaves a warehouse and goes 4 km towards the West. It turns right and goes 9 km, turns right again and goes 16 km, and then turns right once more and goes 4 km. What is the shortest distance between the van and the warehouse now?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 13 km
A right turn moves the facing direction one step clockwise (West → North → East → South). Keep a running total of the distance east (or west) and north (or south) of the warehouse; then use Pythagoras.
Facing West, 4 km: 4 km west of the warehouse
Turns right, now facing North, 9 km: 4 km west, 9 km north
Turns right, now facing East, 16 km: \(16-4=12\) km east, 9 km north
Turns right, now facing South, 4 km: 12 km east, \(9-4=5\) km north
Shortest distance \(=\sqrt{12^{2}+5^{2}}=\sqrt{144+25}=\sqrt{169}=13\) km
The shortest distance is 13 km.
