a man walks at 40kmph and reaches the distance in 10 min less than that of usual . by walking at 60 kmph he reaches 10 minutes earlier. the distance covered by him is.? Choose the correct choice from the following choices
A) 10km	B) 20km	C) 30km	D) 40km	E) 50km
let x be distance in km ,let t be usual time   given 40km/hr=40/60km/min=2/3km/min 10 min less t+10   given 60km/hr=60/60km/min=1km/min 10 min early t-10   since speed=distance/time   2/3=x/t+10.......eq1   1=x/t-10.....eq2   divide eq 1&amp;2   2/3 = t-10/t+10 =&gt; t=50min   x=50-10= 
<gadget id="calculator">50-10</gadget>
<output>40</output>
40km   ANSWER:40km
<result>D</result>
a man walks at 40kmph and reaches the distance in 10 min less than that of usual . by walking at 60 kmph he reaches 10 minutes earlier. the distance covered by him is.?