A man travelled 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	Pick
A) 20  B) 87  C) 276  D) 198  E) 171

Rationale: explanation : average speed = ( 2 × a × b ) / ( a + b ) here a = 25 b = 4 average speed = 2 × 25 × 4 / ( 25 + 4 ) = 200 / 29 kmph . distance covered in 5 hours 48 minutes = speed × time distance = ( 200 / 29 ) × ( 29 / 5 ) = 40 kms distance covered in 5 hours 48 minutes = 40 kms distance of the post office from the village = ( 40 / 2 ) = 20 km . answer : a
Answer: A