Anju starts from Lucknow and drives 18 km towards west. She then takes a right turn, drives 14 km, turns right again and drives 9 km. She takes a final right turn, drives 2 km and stops at Point F. What is the shortest distance between Point F and Lucknow?
Anju starts from Lucknow and drives 18 km towards west. She then takes a right turn, drives 14 km, turns right again and drives 9 km. She takes a final right turn, drives 2 km and stops at Point F. What is the shortest distance between Point F and Lucknow?
Solution
Let's place Lucknow at the starting point and track Anju's position after each turn.
Starting from Lucknow, we can use directions like a compass:
| Movement | Direction | Distance | New Position from Lucknow |
|---|---|---|---|
| Start | - | - | Lucknow (0, 0) |
| First | West | 18 km | 18 km west |
| Right turn → North | North | 14 km | 18 km west, 14 km north |
| Right turn → East | East | 9 km | 9 km west, 14 km north |
| Right turn → South | South | 2 km | 9 km west, 12 km north (Point F) |
Why 9 km west in row 4? She was 18 km west, then moved 9 km east (back towards Lucknow), so: km west
Why 12 km north in row 5? She was 14 km north, then moved 2 km south (back down), so: km north
Point F is 9 km west and 12 km north of Lucknow. This forms a right triangle where:
- One side (horizontal) = 9 km
- Other side (vertical) = 12 km
- Hypotenuse = shortest distance
Using Pythagoras theorem:
km
Answer: Option 4 (15 km)
