If a bus travels 20 km in 30 minutes. what is the average speed of the bus?
a. 20km/h
b. 30km/h
c. 40km/h
d. 50km/h

Answer=C

30minutes=0.5hours

20km/0.5hours=40km/h

Answer=C

If you would like to know what is the average speed of the bus, you can calculate this using the following steps:

20 km ... 30 minutes
x km = ? ... 1 hour = 60 minutes

20 * 60 = 30 * x      /30
x = 20 * 60 / 30
x = 40 km

Result: The average speed of the bus is 40 km/h, so the correct result would be c.