A train moves past a telegraph post and a bridge 264 m long in 8 seconds and 20 seconds respectively. What is the speed of the train?

Answer: (d)

Let the length of the train be L m.

\(\frac{L}{8} = \frac{264+L}{20}\)

20L = 8L + 2112

L = 176 m.

Speed of train = \(\frac{176}{8}\) = 22 m/s = \(22 \times \frac{18}{5}\) = 79.2 km/hr