(c) 25 km/hr
Distance covered by the first person in 10 seconds = \(\bigg[\bigg(3\times\frac{5}{18}\bigg)\times10\bigg]\) m = \(\frac{25}{3}\) m
Distance covered by the second person in 11 seconds = \(\bigg[\bigg(5\times\frac{5}{18}\bigg)\times11\bigg]\) m = \(\frac{275}{18}\) m
∴ The train travels a distance = \(\frac{275}{18} - \frac{25}{3}= \frac{128}{8}\) m in (11 – 10) = 1 second.
∴ Speed of the train = \(\bigg(\frac{125}{18}\times\frac{18}{5}\bigg)\) km/hr = 25 km/hr.