Question

a car covers the first 30 km at a speed of 60 km/h and the next 20 km at 80 km/h find the average speed​

Answer 1

Answer:

66.66 km per hour = $66\frac{2}{3}$ km per hour

Step-by-step explanation:

Speed = Distance / Time

Distance = Speed * Time

Time =  Distance / Speed

First part

Distance = 30 km

Speed = 60 km per hour

=> Time = 30/60 = 0.5 hours

Second part

Distance = 20 km

Speed = 80 km per hour

=> Time = 20/80 = 0.25 hours

Total journey

Distance = 30 + 20 = 50 km

Time = 0.5 + 0.25 = 0.75 hours

=> Speed = 50/0.75 = 66.66 km per hour

Average speed = 66.66 km per hour = $66\frac{2}{3}$ km per hour