A train travelling at a speed of 96 km/h crosses a post in 12 seconds and a platform in 30 seconds. What is the length of the platform?

Correct option is D

Given:

speed of train = 96 km\hr

time taken by train cross post = 12 sec

 time taken by train cross platform = 30sec

Formula Used:

distance = speed $$\times$$ time

solution:

speed of train = 96 km\hr

length of train = speed $$\times$$​ time

                        = $$\frac{96\times 1000\times 12}{3600}$$​  

                     =320meter

length of platform and train =   speed $$\times$$  time

                                           = $$\frac{96\times 1000\times 30}{3600}$$​

                                            =800meters

so length of platform =   length of platform and train  - length of train

                                        =800-320

  so length of platform  =480 meters