Answer:
72 km/h
Step-by-step explanation:
We need to convert units
so:
20 m ----- 1 km -------- 3600 s
1 s ----- 1000 m ----1 h
and solve ot
20 x 1 x 3600 s = 72000 we multiply numerators
1s x 1000 m x 1 h = 1000 we multiply denominators
we divide de results 72000/1000 = 72