A. 27 km/hr

B. 49 km/hr

C. 72 km/hr

D. 92 km/hr

Lost your password? Please enter your email address. You will receive a link and will create a new password via email.

Please briefly explain why you feel this question should be reported.

Please briefly explain why you feel this answer should be reported.

Please briefly explain why you feel this user should be reported.

72 kmph

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

49 km /hr

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

c

A

72km/hr

72 km/hr

72 km/hr

length of train=260

length of wall=120

length=260+120=380

t=19s

s=380/19*18/5=72 km/h

72

C

72

t=d/s

(260+120)/19

20*18/5=72

72

t=d/s

(260+120)/19

20*18/5=72

72

72 km/hr

Answer is 72km/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

49km/hr

72

20 m/secĂ—18/5=

=72kmph

72km/hr

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

72kmph

72

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

72

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]

72

260+120/19

20m/s

also 72kmph

72

72

72km/hr

B. 49

380/19=20 m per sec.

72.. ho my.

1

72km/hr

72km/hr

C

72km/hr

72km/hr

72

C. 72 km/hr

B

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

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?

Total Distance = 260+120=380

Time = 19

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

72

length of train = 260 meters

length of wall = 120 meters

Total length = 380 meters

Remember your answer is in km/hr

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

72km/hr

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

72 kmph

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

72

A