A man starts walking at 3 pm . ha walks at a speed of 4 km/hr on level ground and at a speed of 3 km/hr on uphill , 6 km/hr downhill and then 4 km/hr on level ground to reach home at 9 pm. What is the distance covered on one way  Pick one:
A) 10km  B) 12km  C) 14km  D) 16km  E) 18km
avg speed=2*3*6/(3+6)= 
<gadget id="calculator">2*3*6/(3+6)</gadget>
<output>4</output>
4   so speed of man=4km/hr   distance=4*6= 
<gadget id="calculator">4*6</gadget>
<output>24</output>
24km   since we want one way distance it will be    24/2= 
<gadget id="calculator"> 24/2</gadget>
<output>12</output>
12km   ANSWER:12km
<result>B</result>
A man starts walking at 3 pm . ha walks at a speed of 4 km/hr on level ground and at a speed of 3 km/hr on uphill , 6 km/hr downhill and then 4 km/hr on level ground to reach home at 9 pm. What is the distance covered on one way