The difference between the time taken by two trains to travel a distance of 350 km is 2 hours 20 minutes. If the difference between their speeds is 5 km/hr, what is the speed of faster train ?

Let the speed of the faster train be 'S' kmph

Then speed of the slower train will be '(S-5)' kmph

Time taken by faster train = 350/S hrs

Time taken by slower train = 350/(S-5) hrs

  $\frac{350}{s-5} - \frac{350}{s} = 2 hrs 20 min = 2\frac{1}{3} = \frac{7}{3}$

=> S = 30 km/hr.