| The average speed of a train in the onward journey is 25% more than that in the return journey. The train halts for 2 h on reaching the destination. The total time taken to complete to and fro journey is 32 h, covering a distance of 1600 km. Find the speed of the train in the onward journey. |
A) 56.25 km/h
B) 60 km/h
C) 66.50 km/h
D) 67 km/h
Correct Answer: B
Solution :
| Let speed in the return journey \[=x\] |
| \[\therefore \]Speed in onward journey \[=\frac{125}{100}x=\left( \frac{5}{4}x \right)km/h\] |
| Average speed \[=\frac{2\times \frac{5}{4}x\times x}{\frac{5}{4}x+x}=\frac{10x}{9}km/h\] |
| \[\Rightarrow \]\[1600\times \frac{9}{10x}=30\][since, train halts for 2 h] |
| \[\therefore \] \[x=\frac{1600\times 9}{30\times 10}=48\,\,km/h\] |
| \[\therefore \]Speed in onward journey |
| \[=\frac{5}{4}x=\frac{5}{4}\times 48=60\,\,km/h\] |
You need to login to perform this action.
You will be redirected in
3 sec
