Answer:
8 hours
Explanation:
first car: speed=40, time=(t+3), distance=s1
second car: speed=55, time=t, distance=s2
speed=distance/time
distance=speed×time
s1=40×(t+3)
s2=55×t
since the cars would travel the same distance; s1=s2
40(t+3) = 55t
40t+120 = 55t
15t = 120
t=8