then according to these two time periods we can get two equations

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"So you will not be a simple question,moncler outlet italia, even a child can do it." Many people like to use this spoken to ridicule each other. Yangjiaping of Zhang Xiufeng lives on because the teacher gave the fourth-grade daughter arranged a homework problem to worry about a few days. Results check the Internet and found that this question is high popular online puzzle one example, once stumped 30 students participate in problem-solving. Homework teacher says this channel arrangement job title, intended to train students reasoning ability, and did not let the children have to do it, do not come and will not criticize the child.
 
Daughter homework stumped family
 
I had wanted to take advantage of New Year's Day three days rest Zhang Xiufeng, but because of a homework depressed fourth grade of primary school in Yangjiaping daughter back in. Zhang Xiufeng will stumped their jobs showed a reporter a look, when reporters questions after reading also considers the problem difficult. The original of this question is: a 100 m long row the team is traveling, the messenger came from the discharge end of the first row, and from the first row went to Pai Mei, this column ranks just 100 meters forward, known team speed and the speed of the messenger unchanged! ask how many meters away messenger?
 
"My husband and I wanted a day and a night failed to answer it, so in the 2nd title showed the children her sister did." Zhang Xiufeng, told reporters that his son read to her sister in college. However, her sister's son also failed to answer questions out, and even other college students around him failed to answer it. "When I heard the result of some angry, I feel that the teacher is chaos in assignments, such as college students usually do not even question, let alone fourth-grade students."
 
Originally as online "problem"
 
To be able to do it this road homework, sister of the title son Zhang Xiufeng input Baidu, we found that this problem is on the network a problem Redder, who stumped 30 students participate in problem-solving. There are two answers to this question of the original method, the first method is to use the equation to answer,http://zazna.com/selection/index.php?item/create_form/1, and the second method is to use the ultimate analysis.
 
Zhang Xiufeng think, only fourth-grade primary school children do not need to do such a difficult problem, but also to combat the confidence of children and parents, as they add to the troubles.
 
Teacher: Let children experience the joy of Thinking
 
How is it so hard for the title will be furnished to the children homework when it? Reporters contacted the teacher arranged this question. The teacher said, This question is he inadvertently discovered the Internet, and find it very interesting to the child when it is disposed in the New Year's homework. "This question is certainly beyond the scope of the difficulty children have learned,http://www.shisanming.com/home.php?mod=space&uid=693019, but this title was able to cultivate the children's ability to reason." The teacher said that although the Internet gives the answer is complex, but may have children logical reasoning ability is very Well, the answer will come according to their own methods. And this question is not to have children must do it,moncler pas cher, do not come and will not criticize the child. Mainly in the hope that children can use their brains to think, experience joy in the thought process.
 
 
 
Link
 
How this question is the solution come from?
 
Title: a 100 m long row the team is traveling, the messenger came from the discharge end of the first row, and from the first row walked Pai Mei, this column ranks just 100 meters forward, known speed and messenger team speed remains unchanged! ask how many meters away messenger?
 
A.100 meters
 
B,louboutin soldes femme.200 meters
 
C.300 meters
 
D.100 + 100 * √2 meters
 
E,http://www.aurosiksha.org/login/index.php?item/create_form/1.150 meters
 
F.170.71 meters
 
Answer: D.100 + 100 * √2 meters
 
Two friends of the problem solving process:
 
Method One: first assumed the vanguard of speed is V1,http://my.5754.cn/home.php?mod=spacecp&ac=blog&blogid=,woolrich outlet milano, the team speed is V2, in addition, the vanguard come from Pai Mei Pai Tau distance should be longer than the team,louboutin pas cher, the team longer than this part is assumed to be X, then the vanguard began to return and go Pai Mei went to the team that is starting to go when the first row is not difficult to find the length of his return journey away is X, then according to these two time periods we can get two equations:
 
100 + X / V1 = X / V2
 
X / V1 = 100-X / V2
 
Release V1 / V2 = 100 + X / X = X / 100-X
 
Release the square root of X = 5000
 
Then he walked away = 100 + 2 * 5000 square root, answer D is correct. Really should not be a primary problem
 
Method Two: Limit analysis. Suppose team does not advance, the messenger came back from the head Pai Mei, walking distance is 100 + 100 = 200 m, and then assume the team walked 100 meters, messenger before departure, came back from the head Pai Mei, go away 100 + 100 + 100 = 300 m,http://bbs.zhiliaomei.com/home.php?mod=space&uid=29541, because it is at the same time advancing, so 200 m & lt; messenger away & lt; 300 meters compare answers, only d accord.
 
Voice
 
Beyond acceptable degree of difficulty,http://www.lygyzyz.com/home.php?mod=space&uid=22117, the child will gradually lose interest
 
Shapingba District Newbridge Primary School in ten years teaching elementary school mathematics teacher, said Liu, primary stage of work should not be too difficult,http://xdqvs.com/home.php?mod=space&uid=1747, just right on the line,http://237.newfine.net/home.php?mod=spacecp&ac=blog&blogid=, the teacher will normally be based on the content of the various stages of teaching students, and occasionally interspersed with twelve in homework allow students to use their brains puzzles, students discovery capabilities. But no matter what age is education, we should adhere to the "age-appropriate education." If the student ages beyond acceptable difficulty, the child will gradually lose interest in learning, so that the growth of primary school students are more harm than good. At the same time, parents are to blame for some of the questions, tricky question, to correctly deal.
 
Reporter Liu rain
 
(Original title: This Road Elementary math stumped 30 Students would you do it?)