we had to go 30km through the city and then 30km through the country.Through the city we averaged 40km/h and through the country we averaged 60km/h.What was our average speed for the entire journey ?
2 answers
V = (40+60)/2 = 50 km/h.
Speed= distance/time. At 40km/h you will take 3/4 hours to do 30km. At 60 km you will take 1/2 hours. So, the total time is 3/4 + 1/2 = 1 and 1/4. Hence you will travel 60km in 1 and 1/4 hours => average speed = 6/1 and 1/4= 60x4/5 = 48km.
So, the answer to the question is 48 km/h, not 50km/h. Many people make the same mistake of 50km/h, so don’t worry, you’re not alone if you think so.
So, the answer to the question is 48 km/h, not 50km/h. Many people make the same mistake of 50km/h, so don’t worry, you’re not alone if you think so.
2 answers