A and B are two towns. Mr. Faruqui covers the distance from A to B on cycle at 16 km/hr. however, he cover the distance from B to A on foot at 9 km/hr. his average speed during the whole journey is?
Correct Answer: 11.52 km/hr.
Explanation:
Average Speed = Total distance / time
= 2d / [( d / 16) + ( d / 9)]
= ( 2 x 16 x 9 ) / ( 16 + 9 ).
= 11.52 km/hr. Shortcut : Average speed = 2uv / (u + v)
= ( 2 x 16 x 9 ) / ( 16 + 9 )
= 11.52
