Question

A train running at an average speed of 40 km/hr covers 200 km until it reaches its first stoppage where it stops for a certain time. After a stoppage, the train covers the remaining distance at an average speed of 60 km/hr unit it completes the journey in a total of 10 hours 36 minutes. had the remaining distance been covered at a speed that increases by 10 km/hr every hour starting with 20 km/hr then the remaining distance would have been covered in 51/8 hours, Find the stoppage time? 
1. 34 minutes
2. 32 minutes
3. 36 minutes
4. 38 minutes

Answer 1

Correct Answer - Option 3 : 36 minutes

GIVEN:

Speed for 200 km  = 40 km/hr

speed for remaining distance = 60 km/hr

Total time = 10 hours 36 minutes

Time taken if started with 20 km/hr and increased 10 km/hr every hour = 51/8 hours

FORMULA USED:

Speed = Distance/Time

CALCULATION:

Let the stoppage time be 'x'
Time to cover 200 km = 200/40 = 5 hours

51/8 = 6 + 3/8

Speed will increase by 10 and will be 20, 30,40 ......

Distance = 20 + 30 + 40 + 50 + 60 + 70 + 80 × 3/8 = 300 km

Time taken by actual speed = 300/60 = 5 hours

Also, total time taken is 10 hrs 36 mins

∴  5 + x + 5 = 10 hrs 36 mins

x = 36 minutes 

∴ The stoppage time was 36 minutes.