How long will a train 100 m long and travelling at a speed of 45 kmph, take to cross a platform of length 150 m?
Answer & explanation
Correct answer: option 1
Speed = \(\frac{ Distance}{ Time}\)
Speed of train in m/s = 45 x \(\frac{ 5}{18 }\) = \(\frac{ 25}{2 }\) m/s
Putting values in the formulae:
\(\frac{ 25}{2 }\) = \(\frac{100 + 150}{ Time}\)
Time = \(\frac{\text{250 Χ 2}}{ 25}\)
Time = \(\frac{\text{500}}{ 25}\)
Time = 20 seconds