A person divides his total route of journey into three equal parts and decides to travel the three parts at the speeds of 80 km/h, 60 km/h, and 30 km/h, respectively. What is the average speed during the journey?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 48 km/h.
Let the total distance of the journey = D km
Total Time = [(D/3)/80] + [(D/3)/60] + [(D/3)/30]
= D/240 + D/180 + D/90
= D/48 hours
Average Speed = D/(D/48) = 48 km/h