Question

If a person has to drive 210 km, how long will the journey take if he drives at an average speed of 20 km/hr for 120 km and at an average speed of 30 km/hr for 90 km, and have a 60 minutes stop for refreshments midway through the journey?
1. 7 hours
2. 8 hours
3. 9 hours
4. 10 hours

Answer 1

Correct Answer - Option 4 : 10 hours

Given:

Total distance is 210 km

Formula Used:

Speed = Total distance/Time

Calculation:

In the first part, he traveled, 120 km at 20km/hr.

⇒ Time = Total distance/Speed

⇒ Time = 120/20

⇒ Time = 6 hours

In the second part, he traveled, 90 km at 30km/hr.

⇒ Time = Total distance/Speed

⇒ Time = 90/30

⇒ Time = 3 hours

Total time = 6 + 3 + 1 = 10 hours

∴ Total required time is 10 hours.

 

 

Please don't forget to add the 1 hour of refreshment break to the journey time to get the right answer.