A man starts walking at 3 pm . he 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? Choices.
A) 12	B) 66	C) 77	D) 88	E) 91
lets us consider t1 = time taken on level road. t2 = uphill. t3 = down hill; the distance traveled uphill and down hill same so t2*3= 
<gadget id="calculator">2*3</gadget>
<output>6</output>
6*t3;=&gt; t2 = 2t3;---&gt; (1) total time = 2*t1 + t2 + t3 = 6 hours ---&gt; (2) 2t1+3t3 = 6 --&gt;(3) total distance = 2*(4t1) + 3*t2+ 6*t3 ---&gt; (4) substitute (1) in (4) 8t1 + 12t3 =&gt; 4(2t1+3t3) then from (3) the total distance will become   4*6= 
<gadget id="calculator">  4*6</gadget>
<output>24</output>
24=&gt; one way distance = 12km   12nswer: 12
<result>A</result>
A man starts walking at 3 pm . he 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?