Question

A car travels 40 km in an hour. in the next two hours it travels 78 km. what is the average speed of the car?

Answer 1

To work this out using the speed equation:
 
s = d/t

therefore,

d = 40000m    (km = 1000m) so, 40 * 1000 = 40000
t = 2h

s = 40000/2 = 20000m

s= 20kmh.