Ravi goes to college from his village at the speed of 5km/h and returns at the speed of 4km/h. If he takes 9 hours in all, find the distance (in km) between the village and the college.
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 20.
Let the distance between the village and the college = x km
Time to go from village to college = Speed = 5 km/h and Time = x/5 hour
Time to return from college to village = Speed = 4 km/h and Time = x/4 hours
Total time for the journey = x/5 + x/4 = 9
⇒ (4x + 5x)/20 = 9 ⇒ 9x/20 = 9
⇒ x = (9 × 20)/9 = 20