The distance between two railway stations is 1176 km. To cover this distance, an express train takes 5 hours less than a passenger train while the average speed of the passenger train is 70 km/h less than that of the express train. The time taken by the passenger train to complete the travel is: |
18 hours 17 hours 23 hours 12 hours |
12 hours |
We are given that , Speed = \(\frac{Distance}{Time}\) Let us consider that , Speed of express train = s km/h Speed od passenger train = ( s - 70 ) km/h According to question, \(\frac{1176}{s-70}\) - \(\frac{1176}{s}\) = 5 \(\frac{1176( s - s + 70) }{s(s-70)}\) = 5 \(\frac{1176 (70) }{s(s-70)}\) = 5 s² - 70s - 16464 = 0 By solving it , s = 168 km/h The speed of express train = 168 - 70 = 98 km/h Time taken by express train to travel 1176 km = \(\frac{1176}{98}\) = 12 hours
|