Folosim regula de trei simpla
a) 54km/h............................50m
90km/h............................x m
54/90 = 50 / x → 54 x = 4500
x = 83,3 m
b) 54km/h...........................50m
108km/h ........................y m
54/108 = 50/y
54 y = 5400
y = 100 m