If a 200 m long train crosses a platform of the same length as that of the train in 20 seconds, then the speed of the train is:
Answer & explanation
Correct answer: option 3
Speed = \(\frac{ Distance}{ Time}\)
Speed = \(\frac{\text{200 + 200}}{ 20}\) m/s
Speed = \(\frac{400}{ 20}\) m/s
Speed = 20 m/s
Speed in km/hr:
20 x \(\frac{18 }{ 5}\)
4 x 18 = 72 km/hr
*Note*
In order to convert km/hr to m/s - multiply by \(\frac{ 5}{ 18}\)
In order to convert m/s to kn/hr - multiply by \(\frac{ 18}{ 5}\)