If a man goes from place A to B at a speed of 12 km/h and return at a speed of 18 km/h, then the average speed for the whole journey is:
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option3 i.e. 14 km/h
According to the question
Average distance = Total Distance covered/Total time taken
Average distance = 2xy/(x + y)
where x = 12 km/h and y = 18 km/h
Average distance = (2 × 12 × 18)/(12 + 18)
= (24 × 18)/30 = 14 km/h