Question 90819

    Ralph jogs from his home to the stadium at 10 km/h. His trip home takes exactly one hour less because he takes a car traveling at 60 km/h. How far is it from Ralph's home to the stadium? 


      Let time taken by Ralph to jog from his house to stadium be = x   hrs

                                  His speed is = 10km/hr

           Distance covered by Ralph in x hrs is = 10x kms

        Time taken by him to return by car with  a speed of 60 km/hr is = x-1 hr

         Distance covered by car in (x-1) hr  = 60(x-1)

         since onward and downward distance are same , 60(x-1) = 10x
                                                       60x - 60 = 10x
                                                       60x-10x = 60
                                                             50x = 60
                                                               x = 60/50 = 6/5 

            distance  between Ralph's house and stadium is 10*6/5 = 10.6/5
                                                                  = 2*6 = 12 kms