Question

John walked half the distance to school He realized that he was late and ran the rest of the distance If he walked for 12 minutes and he ran four times as fast as he walked, then the total time taken by John to reach school is _______.
1. 18 min
2. 15 min
3. 21 min
4. 25 min

Answer 1

Correct Answer - Option 2 : 15 min

Given :

John walked half the distance for 12 minutes and ran for the rest distance at 4 times the walking speed.

Concept used :

Distance = speed × time 

Calculations :

Let the speed be s km/min while walking 

Speed while running will be 4s km/min

Let the distance be D 

Distance covered in 12 minutes while walking = 12 × s = 12s 

Remaining distance = 12s 

Time to cover remaining distance = 12s/4s 

⇒ 3 minutes 

Total time of walking and running = 12 + 3 

⇒ 15 minutes 

∴ Option 2 will be the correct choice.