Answer all big emergency will name you bus is on its way pl

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?

Pls the last one and it has to be like number 6

Abox holds 500 paperclips. after a week on the teacher's desk 239 paperclips remained. how many paperclips were used?