A cyclist travels from City X to City Y at an average speed of 30 km/h and takes 5 hours. If they want to complete the same journey in 3 hours, by how many km/h should they increase their average speed?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 20 km/h
Distance between the cities = 30 × 5 = 150 km
New time = 3 hours
New speed needed = 150/3 = 50 km/h
Increase in speed = 50 - 30 = 20 km/h