If one train m long, the length of other train is :
Solution: Question is incomplete if we take first train length 200 m then the respective speed of both trains in opposite side will be (36+45)=81 Km/h
Speed =81 x 5/18
If both trains cross each other in 20 secs then total length of both trains (Distance)= Speed X Time
=45/2X20 =450 m then the length of another train=450-200=250 m
So option (3) will be correct.
Answer: (3) 250 m
Let the length of another train be X m.
The respective speed of both trains in opposite side = 36 + 45
= 81 km/hr
Speed in m/sec = 81 x 5/18
= 9 x 5/2
= 45/2 m/sec
If both trains cross each other in 20 sec
Then, total length of both trains = 45 x 20/2 = (X + 200)
900/2 = X + 200
X = 450 – 200
X = 250 m
Then, the length of another train is 250 m.
Hence, correct answer is option (3) 250 m.