Two friends, Om and Dev, start from the same lamp post. Om walks 12 m towards the North, then turns right and walks 5 m. Dev walks 4 m towards the South, then turns right and walks 7 m. What is the shortest distance between Om and Dev now?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 20 m
A right turn moves the facing direction one step clockwise (North → East, South → West). Find where each friend ends up from the lamp post; then use Pythagoras on the gaps between them.
Om, facing North, 12 m; turns right, now facing East, 5 m: 12 m north, 5 m east of the lamp post
Dev, facing South, 4 m; turns right, now facing West, 7 m: 4 m south, 7 m west of the lamp post
North-south gap \(=12+4=16\) m; east-west gap \(=5+7=12\) m
Shortest distance \(=\sqrt{16^{2}+12^{2}}=\sqrt{256+144}=\sqrt{400}=20\) m
The shortest distance between them is 20 m.
