Johnie went up a certain hill at the rate of one and a half kilometers per hour and came down at the rate of four and a half kilometers per hour, so that it took just four hours to make the double journey. How far was it to the top of the hill ?	Choose the correct choice:  A) 3 km  B) 6 km  C) 4.5 km  D) km  E) none of the above
Assume the distance to the top of the hill (1 way) as: x   Now, speed=distance/time =&gt; time=distance/speed   So, for the first half of the journey, he traveled uphill at 1.5km/hr, so the time taken for the first leg of the journey is: x/1.5.   For the second half, he traveled downhill at 4.5km/hr, so the time taken for the second leg of the journey is: x/4.5   Now, the total time for the trip is given as 4 hrs.   Equating, (x/1.5)+(x/4.5)=4 =&gt; (3x+x)/4.5=4 =&gt; x=4.5 km   So, the distance one side is = 4.5 km.   The OA mentioned is 9km, which is exactly double of this distance, i.e., the total distance traveled during both legs of the journey, but the question only asked for the distance till the top of the hill, i.e., one way, so the answer should be 4.5km   4.5 kman someone assist me in understanding where am I wrong here?
<result>C</result>
Johnie went up a certain hill at the rate of one and a half kilometers per hour and came down at the rate of four and a half kilometers per hour, so that it took just four hours to make the double journey. How far was it to the top of the hill ?