<PRE><B>Question 734095</B>
difference of time  between Train I and Train II 1 hour

speed of train I = 35 kmph

speed of train II = x kmph

catch up speed = x-35

catch up time = 4 hours

catch up distance = 35 km ( distance traveled in 1 hour by Train I)


t= d/s

4 = 35/(x-35)

4(x-35)=35

4x-140=35
4x=140+35
4x=175
x= 43.75 kmph</PRE>