Prep 数学求解解析过程,感谢

ArthurGoal

求答案解析过程

1）

For a certain race, 3 teams were allowed to enter 3 members each. A team earned 6 – n points whenever one of its members finished in nth place, where 1 ≤ n ≤ 5. There were no ties, disqualifications, or withdrawals. If no team earned more than 6 points, what is the least possible score a team could have earned?

•         0
•         1
•         2
•         3
•         4
  

2）The residents of Town X participated in a survey to determine the number of hours per week each resident spent watching television. The distribution of the results of the survey had a mean of 21 hours and a standard deviation of 6 hours. The number of hours that Pat, a resident of Town X, watched television last week was between 1 and 2 standard deviations below the mean. Which of the following could be the number of hours that Pat watched television last week?

•         30
•         20
•         18
•         12
•         6
  

• 
  

ArthurGoal

答案分别是    D 3，    D 12，  C一起成了

lijj0410

1)
3个队伍，每个队伍出3个人，一共9个人。比赛的结果排名就是123456789，其中A team earned 6 – n points whenever one of its members finished in nth place, where 1 ≤ n ≤ 5.就是说第12345名分别可以给自己的队伍加54321分，并且第6789名没有加分。

也就是说这9个人，按照名次第123456789名，
最后分别可以给自己的队伍加  543210000分。

这三个队伍里没有得到6分以上的，问得分最少的一个队伍能得多少分，说明除了得分最少的一个队伍之外另外两个队伍应该得尽量多的分，同时还得保证不超过6分。
那么一个队伍得分5+1+0
一个队伍得分4+2+0
前五名加分里只剩下3分了，那得分最少的这个队伍就是3+0+0

lijj0410

2)
21-6*2<Pat<21-6
9<Pat<15

ArthurGoal

lijj0410 发表于 2018-9-9 11:23
1)
3个队伍，每个队伍出3个人，一共9个人。比赛的结果排名就是123456789，其中A team earned 6 – n points ...

感谢大神，感觉被你一讲就好简单，做的时候怎么也想不明白，第3题能帮忙讲解一下么？

ArthurGoal

第三题木有人回了

ArthurGoal

不好意思，第三题答案给错了，怪不得看不懂答案