A train travels 360 km at a uniform speed. If the speed had been 5 km/h more, it would have taken 1 hour less for the same journey. Find the speed of the train?

We know that,  Speed = Distance/time

Let the speed of the train be = x kmph
           NORMAL SPEED                           SPEED 5 KMPH MORE
          Distance = 360 Km                         Distance =360
 
          speed    =  X Kmph                        Speed = (x+5)
 
            Time =360/X                              Time =360/(x+15)
          

For the same journey if the speed increased 10 kmph more it will take 1 hour less

Time with original speed - time with increased speed = 1
 => (360/x) - (360/x+10) =  1                               
 =>  (360(x+5)-360x)/x(x+5) =1
 =>   360X + 1800 -360X  = X(X+5)
  =>   X^2 + 5x - 1800 = 0
  X = 40 or -45
 X cannot be negetive value
                  

 X = 40 kmph.