zeeny
Sep 28, 2013, 04:45 AM
A man travels 5km at the speed of 20kmph... from there he travels 20km at the speed of 40kmph.. what's the average speed?
15yearoldgirl
Nov 9, 2013, 04:44 PM
Start by finding the time each part takes as this is a value you can add, unlike the speeds:
Time = Distance/Speed
5/20 = 0.25 hours = 15 minutes
20/40 = 0.5 = 30 minutes
Total distance = 25 km
Total time = 0.75 hours = 45 minutes
Speed = Distance/Time
Average speed = 25/0.75
Average speed = 33.3 kmph
If you need the answer in a different unit you will have to convert FIRST. Hope this was helpful.