Answer:
70 km/h
Explanation:
Let the velocity of car A is v km/h, thus the velocity of car B is (v - 20) km/h.
They meet after 3 hours.
Distance traveled by car A in 3 hours = v x 3 = 3 v
Distance traveled by car B in 3 hours = (v - 20) x 3 = 3v - 60
Total distance traveled is 480 km
So, 3 v + 3 v - 60 = 480
6 v - 60 = 480
6 v = 540
v = 90 km/h
Thus, the speed of car A is 90 km/h and the speed of car B is 90 - 20 = 70 km/h.