3牛吃草问题（3 cattle grazing problem）.docVIP

3牛吃草问题（3 cattle grazing problem） One example of Jingjiang In 1. cases there is a pasture, pasture grass every day in the uniform growth of the pasture for 15 cows to eat for 20 days, or for 20 cows eat for 10 days. Then, the pasture grass of the daily life for a few cows to eat in a day? 2. cases of pasture covered with grass, for 24 cows eat for 6 weeks or 9 weeks for 23 cows to eat. If a week even growth of grass. Ask the original amount available for a few cows eat grass for 1 weeks? 3. a piece of grass, every day the growth rate is the same, now this piece of grass for 16 cows to eat for 20 days, or 80 sheep to eat for 12 days, if the amount of grass a cow a day to eat the grass is equal to 4 sheep a day to eat, then eat 10 oxen and 60 sheep, can for how many days? 4. cases of pasture, grass grows every day at the same speed, now, this piece of grass for 20 cows to eat for 12 days, or 60 sheep to eat for 24 days. If a cow eat grass every day is equal to 4 sheep eat grass every day, then, 12 cows with 88 sheep can eat how many days? 5. cases due to cold weather, pasture grass every day at a uniform speed reduction, by calculation, the existing meadows for 20 cows eat for 5 days, and 16 cows eat for 6 days, then, 11 cows can eat a few days? 6. cases due to cold weather, pasture grass every day at a fixed rate. Known to a pasture grass for 20 cows to eat for 5 days, or 12 cows eat for 7 days, so for 6 cows to eat for a few days? 7. passengers began queuing at the ticket that just before several minutes, the same number of passengers per minutes. If the 4 wicket, from the beginning to wait for the ticket ticket team disappeared, 30 minutes; at the same time to open 5 wicket, 20 minutes, if at the same time to open the 7 wicket, then how many minutes team disappeared? 8. cases of a train station ticket gate at the start of the ticket before has 945 passengers waiting for ticket. At this time, every minute and fixed some people come to the entrance ready to stop. If t