78. A train 360 m long is running at a speed of 45 km/hr. In what time will it pass a bridge 140 m long?

✅ The correct answer is option A.
Formula for converting from km/hr to m/s:  
X km/hr =

X x
5

m/s.

18

Therefore, Speed =

45 x
5
m/sec
=
25
m/sec.

18
2

Total distance to be covered = (360 + 140) m = 500 m.

Formula for finding Time =

Distance

Speed

Required time =

500 x 2
sec
= 40 sec.

25