A cyclist rides for 2 hours at 15 km/hr and then for 3 hours at 20 km/hr. What is the average speed (in km/hr) of the cyclist for the entire trip?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e.18.
Average = Total distance/total time
Distance in 1st part = 15 × 2 = 30 km
Distance in 2nd part = 20 × 3 = 60 km
Total distance = 30 + 60 = 90 km
Total time = 2 + 3 = 5 hours
Average speed = 90 ÷ 5 = 18 km/hr