• -7

# A 260 meter long train crosses a 120 meter long wall in 19 seconds. What is the speed of the train? A. 27 km/hr B. 49 km/hr C. 72 km/hr D. 92 km/hr

• -7
A 260 meter long train crosses a 120 meter long wall in 19 seconds. What is the speed of the train?
A. 27 km/hr
B. 49 km/hr
C. 72 km/hr
D. 92 km/hr
Share

1. 72 kmph

2. A 260 meter long train crosses a 120 meter long wall in 19 seconds. What is the speed of the train?
Speed=Distance/Time
Distance=length of train+ length of wall(260+120)
so, Distance=380m
Time=19 sec
Speed=380m/19 sec
=20m/sec
in the options it is in km/hours so by converting we get
20m/sec*18/5=72km/hr

3. 49 km /hr

4. Total Distance Cover by the train in 19 sec = 260+120=380 meter
speed of train is (380 * 3600)/19=72000meter/h
Km/h=72000/1000=72km/h

5. c

6. A

7. 72km/hr

8. 72 km/hr

9. 72 km/hr

10. length of train=260
length of wall=120
length=260+120=380
t=19s
s=380/19*18/5=72 km/h

11. 72

12. C

13. 72

t=d/s
(260+120)/19
20*18/5=72

14. 72

t=d/s
(260+120)/19
20*18/5=72

15. 72

16. 72 km/hr

Solution
Speed=distance*time
Here distance = 360(length of the train + length of the bridge)
Speed =360*19*(18/5) here(18/5) is used for converting m/s to km/hr
Speed =72km/hr

18. 49km/hr

19. 72

20. 20 m/secĂ—18/5=
=72kmph

21. 72km/hr

22. C. 72 KM/Hour
The length of the train L is 260 Mts and the length of the wall is 120 Mts which we call it as D and the time T taken is 19 Secs
Speed in Mts/Sec = ( L + D)/T = (260 + 120)/19 = 380/19 = 20M/S
Converting the same to hours per km
20 * 3600 = 72000 Mts/Sec = 72000/1000 = 72 Kms

23. 72kmph

24. 72

25. total dis=380
time taken to travel=19 sec
S=d/t
s=380/19
=20
to covert m/s to km/per we have to multiply with 18/5
so 20m/s in km/h is
20m/s=20*18/5=72km/hr

26. 72

27. 260+120=380 m
time=19 s
speed= 380/19 m/s=20 m/s
in km, speed= (20*3600)/1000 [ 1 hour= 3600 s]

28. 72

29. 260+120/19
20m/s
also 72kmph

30. 72

31. 72

32. 72km/hr

33. B. 49

380/19=20 m per sec.

• 72.. ho my.

34. 1

35. 72km/hr

36. 72km/hr

37. C

38. 72km/hr

39. 72km/hr

40. 72

41. C. 72 km/hr

42. B

43. Total distance = 260+120=380m
Time = 19sec
Speed of train in (m/sec) = total distance/ Time
= 380/19=20m/sec
Convert m/sec to km/hr. Short cut(*ly 3.6)
20*3.6= 72

44. I understand the above answers but when the train has to completely pass the 120 m wall/tunnel, shouldnt the end of train be at the rear end of tunnel? which means distance = 260 + 120 + 260?

45. Total Distance = 260+120=380

Time = 19

Speed of Train = (380/19) x (18/5) => 40 K/hr

46. 72

47. length of train = 260 meters
length of wall = 120 meters
Total length = 380 meters
so convert length to km by dividing by 1000
Hence total length = 380/1000 =0.38

Time is 19 seconds, convert to hr by dividing by 120
19/120 = 0.00528 hr

Speed =distance/time……………0.38/0.00528 =71.97km/hr

• 19/3600 =0.00528
3600 seconds give 1hour

48. 72km/hr

49. length of the train is = 260 m
length of the platform is = 120m
so total length is = 380m
and time taken is = 19s
so v = 380/19
v = 20m/s

50. 72 kmph

51. train’s length=260m
wall=120m
time=19sec
speed=distance/time
distance=train’s length+ wall’s length
so, speed=(260+120)/19=20m/s
in kms, speed=20*(18/5)=72Km/hr

52. 72

• A