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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

✅ Correct Option: 4

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:

MovementDirectionDistanceNew Position from Lucknow
Start--Lucknow (0, 0)
FirstWest18 km18 km west
Right turn → NorthNorth14 km18 km west, 14 km north
Right turn → EastEast9 km9 km west, 14 km north
Right turn → SouthSouth2 km9 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: 18−9=918 - 9 = 9 km west

Why 12 km north in row 5? She was 14 km north, then moved 2 km south (back down), so: 14−2=1214 - 2 = 12 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: Distance2=92+122\text{Distance}^2 = 9^2 + 12^2

Distance2=81+144=225\text{Distance}^2 = 81 + 144 = 225

Distance=225=15\text{Distance} = \sqrt{225} = 15 km

Answer: Option 4 (15 km)

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