Please help I don't understand where u am making my mistake ​

Acar started driving from city a to city b, distance between which is 620 miles, at a rate of 60 mph. two hours later a truck left city b and started moving towards city a at a rate of 40 mph. how many hours after the truck's departure will the two meet?

Two cars which are 40 miles apart start moving simultaneously in the same direction with constant speeds. if the speed of the car which is behind is 56 mph and the speed of the other car is 48 mph, how many hours will it take for the car which is behind to catch up the car ahead of it?

Which of the following disjunctions is true? 4 + 4 = 16 or 6 - 5 = 11 4 · 3 = 7 or 3 - 2 = 5 8 - 5 = 13 or 7 · 2 = 12 7 - 4 = 11 or 6 + 3 = 9