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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 ?
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- 56.25 km/h
- 60 km/h
- 66.50 km/h
- 67 km/h
Correct Option: B
Let speed in the return journey = V
∴ Speed in onward journey = (125/100) x V = 5V/4 km/h
Average speed = (2x 5V/4 x V) / (5V/4 + V) = 10V/9 km/h
∴ 1600 x (9/10V) = 30 [∴ halts for 2 h ]
∴ V = 1600 x 9/30 x 10 = 48 km/h
∴ Speed in onward journey = 5V/4 = 5/4 x 48 = 60 km/h
Comments
MD.SHAHANUR
June 21, 2018Let, The speed of return journey be 20k
and the speed of onward journey be 20k x 1.25 = 25k
According to question,
(800/20k) + (800/25k) = 32-2
=》k = 2.4
Now, onward journey's speed be 2.4 × 25 = 60 kmph