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?

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

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