Question

A train travelling at 48 kmph completely crosses another train having half its length and travelling in opposite direction at 42 kmph in 12 s. It also passes a railway platform in 45 s. The length of the platform is: select one:

a. 320m

b. 425m

c. 400m

d. 350m

Answer 1

Answer:

sorry dude I don't know the answer.

Answer 2

Answer:

400m

Explanation:

Let the length of the first train be x metres.

Then, the length of the second train is (x/2)metres.

relative speed=(48+42)kmph=(90×5/18)m/s=25m/s

[x÷(x/2)]/25=12or3x/2=300 or x=200

length of first train =200m.

let the length of platform be y meters.

speed of the first train=(45×6/18)=40/3m/s.

(200+y)×3/40=45

=>600+3y=1800

=>y=400m

pls mark this as brainlist answer