A man traveled from the village to the post-office at the rate of 25 kmph and walked back at the rate of 4 kmph. If the whole journey took 5 hours 48 minutes, find the distance of the post-office from the village ?	Choose the correct choice:
A) 70 m  B) 80 km  C) 20 km  D) 10 km  E) 73 km
Explanation:   Average speed = , here a=25 b=4   = 2x25x4/(25+4) = 200/29 km/hr.   Distance covered in 5 hours 48 minutes   = Speed x time = (200/29)x (29/5) Distance covered in 5 hours 48 minutes = 40kms.   Distance of the post office from the village = (40/2)= 
<gadget id="calculator">(40/2)</gadget>
<output>20</output>
20 km.   Answer: 20 km
<result>C</result>
A man traveled from the village to the post-office at the rate of 25 kmph and walked back at the rate of 4 kmph. If the whole journey took 5 hours 48 minutes, find the distance of the post-office from the village ?