1.\x05The distance between A and B is 360km/h and one is rid

1.\x05The distance between A and B is 360km/h and one is riding a bike from A at the speed of 20 km/h,the other is riding a motorcycle from B .As is know that motorcycle’speed is four times faster than bicycle and their traveling direction is the same.If the person who rides a bike starts 2 hours earlier ,how much time does the motorcycle need to catch up with the bike?
2.\x05half an hour later.Question:if they walk in the same direction ,how many hours will John take to catch up with Tony?
3.\x05The distance between A and B is 234km.It takes one boat 9 hours from A to B ,if the boat returns from B to A ,it will take the boat 13 hours,Question:what is the speed of the boat in still water and the speed of water-flow respectively?
4.\x05The distance between port A and port B is 360km,it takes a ship 35 hours to cross and recross once between the two ports,it takes the ship in countercurrent direction 5 hours more than which in downstream direction.We know that the speed of still water is 12km/h,Question:How many hours will the boat take when it cross and recross once between the two ports?
5.\x05The length of a tunnel is 360m,if a train goes into the tunnel from its first carriage(车厢) to its last carriage and the whole train is in the tunnel,the train needs 8 seconds.If its first carriage goes into the tunnel and the last carriage goes out of the tunnel,the train needs 20 seconds.Question:how long is the train?

2/3小时 第二题不明白意思 静水22千米/小时,水流速度4千米/小时 第四题不明白意思 40米 英语实在太难了.