Question

7. A 225 m long train crosses another 150 m long train in 12.5 s. If one of the trains travels @ 72 km/h, what is the speed of the other? (1) 54 km/h (2) 27 km/h (3) 36 km/h (4) 45 km/h (5) None of these​

Answer 1

Answer:

Total length :225+150=375 m

Time :12.5 s

Speed of one train:72 km/h =20 m/s

speed of another train = x m/s

Speed=distance/time

If both trains move in opposite direction

20+ x =375/12.5

20+ x = 30

x = 30–20=10 m/s

If both trains move in the same direction

x -20 =30

X= 50 m/s