A salesman travels a distance of 50 km in 2 hours and 30 minutes. How much faster in kilometer per hour, on an average, must he travel to make such trip in 5/6 hour less time?
Options.
A) 10km/hr  B) 15km/hr  C) 20km/hr  D) 30km/hr  E) 25km/hr
Time required = 2 hrs 30 min - 50 min = 1 hr 40 min = 1 2/3 hrs   Required speed = 50*3/5= 
<gadget id="calculator">50*3/5</gadget>
<output>30</output>
30km/hr   Original speed= 50*2/5= 
<gadget id="calculator">50*2/5</gadget>
<output>20</output>
20 km/hr   Difference= 30-20= 
<gadget id="calculator">30-20</gadget>
<output>10</output>
10 km/hr   10km/hrnswer is 10km/hr
<result>A</result>
A salesman travels a distance of 50 km in 2 hours and 30 minutes. How much faster in kilometer per hour, on an average, must he travel to make such trip in 5/6 hour less time?