1.\x05A,B and C have a race of 200 meters,when A arrives at

1.\x05A,B and C have a race of 200 meters,when A arrives at the destination,B is 20 meter far from the destination(终点),C is 25 meters far from the destination.Question:if they don’t change their speeds,How far is C from the destination when B reaches the destination?
2.\x05If a boat leaves dock A for dock B in downstream direction,(顺行) it will take 6 hours and if the boat leaves dock B for A in countercurrent direction(逆行),it will take 7 hours .We know that the water-flow(静水)speed is 3km/h,please calculate the speed of boat traveling in still water.
3.\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?
4.\x05Lily and Lucy run along a 600 meters long runway.If they run in the reverse direction at the same time and spot,they will encounter in 6 minutes,and if they run in the same direction at the same time and spot,lily will catch up with lucy in 12 minutes.So how far do Lily and Lucy run per minute?
5.\x05Thereis a boat traveling between A and B .We know the boat’s speed in still water is 9 km/h and the speed ratio of in countercurrent direction(逆行) and in downstream direction(顺行) is 2:1 ,but if one day it rains,the speed of water became twice as before ,so it took the boat 10 hours to return between A and B ,Question:How far is it between Aand B
10.\x05The speed ratio between John and Tony is 7:5,John starts from A ,Tony starts Lily and Lucy run along a 600 meters long runway.If they run in the reverse direction at the same time and spot,they will encounter in 6 minutes,and if they run in the same direction at the same time and spot,lily will catch up with lucy in 12 minutes.So how far do Lily and Lucy run per minute?

1）简单说明一下题意,abc有200m的行程,当a到达终点的时候,b还有20m,c还有25m,那么可以求出abc的速度比a:b:c=200:(200-20)：(200-25)=40:36:35,当b到达时,c距终点还有200-200*35/36≈5.56m
2）从a到b顺行要6个小时,从b到a逆行要7个小时,已知静水速度为3km/h,求船在静水中的速度.设船在静水中的速度为xkm/h,（x+3）*6=（x-3）*7,解得x=39km/h
再问： 我只要答案 还有其他题的呢？速度啦！
再答： 3）设须用时x小时，80x=20*2+20x，解得x=2/3 4）设lucy速度为xm/min，lily为ym/min，列方程组①（x+y）*6=600，②（x-y）*12=600，解得x=75，y=25
再问： 恩恩 还有一题我就采纳你
再答： 5）在静水中9km/h，v逆水：v顺水=1:2，则v船=27km/h，实际速度为27-9*2=9，那么距离为9*10=90km