Question

29. A man travels 370km partly by train and partly by car. If he covers 250km by train and the rest by car, it takes him 4 hours. But, if he travels 130km by train and the rest by car, he takes 18 minutes longer. Find the speed of the train and that of the car

Answer 1

heya......


Let the speed of the car be C kmph

Let the speed of the train be T kmph


4 hours = 250 km / T kmph + (370 - 250) km / C kmph


         4 = 250/T + 120/C  -- equation 1


4 hrs 18 minutes = 130 km / T kmph + (370 - 130)km / C kmph

       258/60 = 4.3 = 130 / T + 240 / C      --- equation 2


Multiply equation 1 by 2 and subtract equation 2 from it.


       8 - 4.3 = 500/T - 130/T + 240/C - 240/C


       3.7 = 370 / T


       T = 370/3.7 = 100 kmph


Substitute the value of T in equation 1 to get,


       4 = 250/T + 120/C  -- equation 1

       4 = 250/100 + 120/C

       4 - 2.5 = 120/C


       C = 120/1.5 = 80 kmph


The train runs at 100 kmph and the car runs at 80 kmph


tysm...#gozmit