A train covers a distance in 50 minutes, if it runs at a speed of 48kmph on an average. Find the speed at which the train must run to reduce the time of journey to 40 minutes. Choose the correct choice.
A) 70 km/hr
B) 60 km/hr
C) 10 km/hr
D) 20 km/hr
E) 30 km/hr
Explanation:   We are having time and speed given, so first we will calculate the distance. Then we can get new speed for given time and distance.   Lets solve it.   Time = 50/60 hr = 5/6 hr   Speed = 48 mph   Distance = S*T = 48 * 5/6= 
<gadget id="calculator">48 * 5/6</gadget>
<output>40</output>
40 km   New time will be 40 minutes so,   Time= 40/60 hr = 2/3 hr   Now we know,   Speed = Distance/Time   New speed = 40*3/2= 
<gadget id="calculator">40*3/2</gadget>
<output>60</output>
60kmph   Answer: 60 km/hr
<result>B</result>
A train covers a distance in 50 minutes, if it runs at a speed of 48kmph on an average. Find the speed at which the train must run to reduce the time of journey to 40 minutes.