you are driving home from school at 90 km/h. it then began to rain and you slow to 50km/h. your arrive home after driving 3 hours and 20 minutes, how far is your hometown from school? what is the average speed?

Answer 1

No unique solution.

20'@90 + 3h@50 = 30+150 = 180km
1h20'@90 + 2h@50 = 120+100 = 220km
2h20'@90 + 1h@50 = 210+50 = 260km

Some info is missing.